CA2431535A1 - Colloidal catalyst - Google Patents
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- CA2431535A1 CA2431535A1 CA 2431535 CA2431535A CA2431535A1 CA 2431535 A1 CA2431535 A1 CA 2431535A1 CA 2431535 CA2431535 CA 2431535 CA 2431535 A CA2431535 A CA 2431535A CA 2431535 A1 CA2431535 A1 CA 2431535A1
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Abstract
Catalytically active sols and methods for making the catalyst sols are described. Said sols are comprised in part of dispersions of transition metal dichalcogenide colloidal particles suspended in a fluid matrix. These materials are useful in a wide range of catalytic reactions. They are particularly useful in petroleum catalysis reactions.
Description
TITLE: COLLOIDAL CATALYST
INVENTORS: David Deck Rending CROSS REFERENCE TO RELATED APPLICATIONS:
Reference is hereby made to commonly assigned provisional U.S. Patent application NOVEL CATALYST STRUCTURES, application No. 60/310583, filed August 7, 20(11, the benefit of which is hereby claimed and the disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION:
This invention is directed to novel, high surface area, unsupported catalyst dispersions.
These dispersions are preferentially made from exfoliated MoSz and WS2, with and without promoters, and have been used to catalytically convert heavy hydrocarbons into lighter oils having lower boiling points. It is likely that they will find use in a wide range of processes that derive benefit from dispersed catalysts.
BACKGROUND OF THE INVENTION:
A number of processes that beneficially use transition metal dichalcogenide dispersed catalysts have been disclosed. While not intending to limit the scope of the present invention, typical examples of processes may be found in, Cox et al., in US.
Patent 4,155,832, which describes the benefit of using dispersed catalysts in the hydrogenation of coal, and in US. Pat. No. 4,557,821 Lopez et al., which describes the use of dispersed catalyst to hydro-process heavy oils.
Typically, these catalysts are synthesized from relatively expensive water-soluble or oil-soluble molybdenum or tungsten precursors, and must be converted into sulfides either prior to application or in-situ. Many examples of dispersed catalysts of this type may be found in literature, typical examples of these dispersed catalysts may be found in US.
Patents, 5,578, I 97, 5,094,991 and 5,916,432. It would be beneficial if the catalysts could be made from less expensive, naturally occurring bulk materials.
Further, the pre or in-situ sulfideing processes necessary to activate the previously disclosed dispersed catalysts are either complex and expensive - if conducted prior to use, or inherently inefficient if performed in-situ - because the catalyst does not function until the precursor has been converted. It would be beneficial if the catalysts could be made with simpler processes and could be comprised of materials that do not require presulfideing or conversion.
In US. Patent 4,822,590 Morrison et al., describe methods for producing novel layered materials from layer type dichalcogenides such as MoSz, TaS~. WSZ, and the like, that have been exfoliated by intercalation of an alkali metal and immersion in water, then restacked, and dried. The '590 patent also describes how various species such as compounds of Co, Ni, Pb, Cd, Al, Ce, In, and Zn may be adsorbed as monolayers on the exfoliated sheets or precipitated as clusters between the sheets, to form inclusion compounds when the sheets are re-stacked or re-crystallized. The inclusions can be converted to catalytically active species during the drying process as described by Morrision et al, in US. Patent 4,853,359. In US Patent 4,99,108 and US Patent 6,143,359 Divigalpitiya et al., and Rending respectively disclose methods for expanding the range of materials that can be adsorbed on or included within re-stacked sheets to include miscible organics with and without solutes, immiscible organics, and metal-organic materials. In many respects the materials described in preceding disclosures make ideal candidates for dispersed catalysts. The methods and materials described in the "590, 1 (18, and both of the 359" patents are incorporated into the present invention by reference.
However, in all the materials described, once the exfoliated materials have been restacked and dried, the particle size becomes too large to provide a stable dispersion when re-suspended. It would be beneficial if materials exhibiting similar or greater catalytic activity to those described above could be formed into particles small enough to form stable colloids.
The surface area and structure of a catalyst can be just as important as the selection of the type of promoter in determining the activity and specificity of the catalyst in a desired reaction. It would be beneficial if methods could be developed to control the morphology of the dispersed catalyst particles, with and without promoters, in a range of sizes and shapes that suit the specific reaction of their application.
Finally the "590, 108, and both of the 359" patents describe steps in their processes where, at some point, exfoliated transition metal dichalcogenides are suspended in water, or miscible organics, or at a water/immiscible organic interface. Miscible organic solvents are often expensive and environmentally dangerous materials. Water or other erotic suspension mediums may be detrimental in certain processes such as hydrotreating.
It would be beneficial if methods could be found to optionally suspend exfoliated transition metal dichalcogenides in immiscible organic liquids such as oil.
SUMMARY OF THE INVENTION:
The present inventors have made extensive studies with the view toward developing more versatile dispersed catalysts. As a result, new methods have been found that not only simplify the production of colloidal particles but also give much greater control over particle morphology, activity, and selectivity. Catalytically active dispersions are disclosed and methods for producing dispersions of catalytically active colloidal particles suspended in Brownian motion within a fluid matrix where said particles fall into three dimensional ranges. Said dimensional ranges are -( 1 ) Nano-dimensional sheets having:
a) Thickness (z) dimensions between 0.5 and 10 nanometers of the selected catalytically active material, and b) Lengths (x) between >1 nanometers and up to 100 nanometers, and c) W idths (y) between > I nanometers and up to I 00 nanometers (2) Macro-molecules having:
a) A thickness (z) dimension between 0.5 and 100 nanometers of the selected catalytically active material, and b) Lengths (x) of between 100 nanometers and 150 microns, and c) Widths (y) of between 100 nanometers and 150 microns.
INVENTORS: David Deck Rending CROSS REFERENCE TO RELATED APPLICATIONS:
Reference is hereby made to commonly assigned provisional U.S. Patent application NOVEL CATALYST STRUCTURES, application No. 60/310583, filed August 7, 20(11, the benefit of which is hereby claimed and the disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION:
This invention is directed to novel, high surface area, unsupported catalyst dispersions.
These dispersions are preferentially made from exfoliated MoSz and WS2, with and without promoters, and have been used to catalytically convert heavy hydrocarbons into lighter oils having lower boiling points. It is likely that they will find use in a wide range of processes that derive benefit from dispersed catalysts.
BACKGROUND OF THE INVENTION:
A number of processes that beneficially use transition metal dichalcogenide dispersed catalysts have been disclosed. While not intending to limit the scope of the present invention, typical examples of processes may be found in, Cox et al., in US.
Patent 4,155,832, which describes the benefit of using dispersed catalysts in the hydrogenation of coal, and in US. Pat. No. 4,557,821 Lopez et al., which describes the use of dispersed catalyst to hydro-process heavy oils.
Typically, these catalysts are synthesized from relatively expensive water-soluble or oil-soluble molybdenum or tungsten precursors, and must be converted into sulfides either prior to application or in-situ. Many examples of dispersed catalysts of this type may be found in literature, typical examples of these dispersed catalysts may be found in US.
Patents, 5,578, I 97, 5,094,991 and 5,916,432. It would be beneficial if the catalysts could be made from less expensive, naturally occurring bulk materials.
Further, the pre or in-situ sulfideing processes necessary to activate the previously disclosed dispersed catalysts are either complex and expensive - if conducted prior to use, or inherently inefficient if performed in-situ - because the catalyst does not function until the precursor has been converted. It would be beneficial if the catalysts could be made with simpler processes and could be comprised of materials that do not require presulfideing or conversion.
In US. Patent 4,822,590 Morrison et al., describe methods for producing novel layered materials from layer type dichalcogenides such as MoSz, TaS~. WSZ, and the like, that have been exfoliated by intercalation of an alkali metal and immersion in water, then restacked, and dried. The '590 patent also describes how various species such as compounds of Co, Ni, Pb, Cd, Al, Ce, In, and Zn may be adsorbed as monolayers on the exfoliated sheets or precipitated as clusters between the sheets, to form inclusion compounds when the sheets are re-stacked or re-crystallized. The inclusions can be converted to catalytically active species during the drying process as described by Morrision et al, in US. Patent 4,853,359. In US Patent 4,99,108 and US Patent 6,143,359 Divigalpitiya et al., and Rending respectively disclose methods for expanding the range of materials that can be adsorbed on or included within re-stacked sheets to include miscible organics with and without solutes, immiscible organics, and metal-organic materials. In many respects the materials described in preceding disclosures make ideal candidates for dispersed catalysts. The methods and materials described in the "590, 1 (18, and both of the 359" patents are incorporated into the present invention by reference.
However, in all the materials described, once the exfoliated materials have been restacked and dried, the particle size becomes too large to provide a stable dispersion when re-suspended. It would be beneficial if materials exhibiting similar or greater catalytic activity to those described above could be formed into particles small enough to form stable colloids.
The surface area and structure of a catalyst can be just as important as the selection of the type of promoter in determining the activity and specificity of the catalyst in a desired reaction. It would be beneficial if methods could be developed to control the morphology of the dispersed catalyst particles, with and without promoters, in a range of sizes and shapes that suit the specific reaction of their application.
Finally the "590, 108, and both of the 359" patents describe steps in their processes where, at some point, exfoliated transition metal dichalcogenides are suspended in water, or miscible organics, or at a water/immiscible organic interface. Miscible organic solvents are often expensive and environmentally dangerous materials. Water or other erotic suspension mediums may be detrimental in certain processes such as hydrotreating.
It would be beneficial if methods could be found to optionally suspend exfoliated transition metal dichalcogenides in immiscible organic liquids such as oil.
SUMMARY OF THE INVENTION:
The present inventors have made extensive studies with the view toward developing more versatile dispersed catalysts. As a result, new methods have been found that not only simplify the production of colloidal particles but also give much greater control over particle morphology, activity, and selectivity. Catalytically active dispersions are disclosed and methods for producing dispersions of catalytically active colloidal particles suspended in Brownian motion within a fluid matrix where said particles fall into three dimensional ranges. Said dimensional ranges are -( 1 ) Nano-dimensional sheets having:
a) Thickness (z) dimensions between 0.5 and 10 nanometers of the selected catalytically active material, and b) Lengths (x) between >1 nanometers and up to 100 nanometers, and c) W idths (y) between > I nanometers and up to I 00 nanometers (2) Macro-molecules having:
a) A thickness (z) dimension between 0.5 and 100 nanometers of the selected catalytically active material, and b) Lengths (x) of between 100 nanometers and 150 microns, and c) Widths (y) of between 100 nanometers and 150 microns.
(3) Mesoscopic particles:
a) Where no particle dimension exceeds 1 micron Finally a method for dispersing said particles in immiscible liquids, such as oil, is disclosed.
DESCRIPTION OF DRAWINGS
Drawing Sheet 1 - Depicts X-ray diffraction methods employed to determine the production the preferred nano-dimensional sheets made from MoS~ into completely exfoliated MoSz is compared with partially exfoliated MoSz and bulk crystalline (unexfoliated) MoSz.
Spectrum (201) exhibits sharp peaks at approximately 28 = 14°, 29°, 33° 39° and 49°
corresponding to the (002), (004), (100), (103) and (105) among other crystal planes.
These peaks are consistent with bulk crystalline MoS2. Exfoliated MoS2 (Spectrum 203) exhibits an asymmetric broadening of the ( 100) plane with a saw-tooth pattern, and has the presence of the ( 110) peak at 58°. Exfoliated MoS2 is also confirmed by the absence of (001) peaks such as the (002) peak at 14°, which would indicate periodicity in the c-axis. Partially exfoliated MoS2 (Spectrum 202) is very similar to that of exfoliated MoS2 except that it exhibits a peak at 14° that indicates stacking of the MoS2 sheets in the c-direction.
DI'awing Sheet 2 - is an illustration of some of the forms of materials of the present invention (301) nano-dimensional sheets, (302) macro-molecular sheets, (303) mesoscopic solid porous structures, (304) three-dimensional semi-solid structures where the lighter circles represent liquid inclusion materials.
Drawing Sheet 3 - is an illustration of the range of orientation of nanodimensional and macro-molecular sheets used to form micro-structures. Number 401 represents nano-dimensional sheets organized to form a microstructure with sheets in a parallel orientation. Number 402 represents various size sheets in a perpendicular orientation forming a porous microstructure. In the figure, the light colored ends correspond to negative charges on the edge sites. Mote that these negative charges will also exist on edges perpendicular to the page where the exfoliated transition dichalcogenide sheet is exposed in this case. The positive charges on the other hand exist on the basal plane and are attracted to the edge sites. The attraction of the basal plane to the edge sites forms the porous organized structure.
Drawing Sheet 4 - depicts a comparison of conversion rates achieved by the products detailed in experiments 4-6.
Drawing Sheet 5 - depicts a comparison of the coke formation achieved by the products detailed in experiments 4-6 DI'aW111g Sheet 6 - depicts a comparison of the sultur removal achieved by the products detailed in experiments 4-6 DI'aW111g Sheet 7 - depicts a comparison of the simulated distillation of the products derived from experiment 4-6 DETAILED DESCRIPTION OF THE INVENTION:
A brief description of sol-gel processes may assist in understanding the techniques disclosed.
For the purposes of this invention the word sol-gel does not describe a product but instead describes a reaction mechanism whereby a sol, which is a colloidal suspension of solid particles in a liquid, transforms into a gel due to the growth and interconnectedness of the solid particles. One theory of the operation of the reaction mechanism is that through continued reactions within the sol, one or more molecules in the sol may eventually reach macroscopic dimensions so that it/they form a solid network that extends substantially throughout the sol. At this point (called the gel point), the substance is said to be a gel. By this definition, a gel is a substance that contains a continuous solid skeleton enclosing a continuous liquid phase. Open-pored solid structures are formed by removing the liquid phase without collapsing the solid skeleton. Techniques, such as inclusions of surfactants, using bacteria as templates, and a wide. variety of other methods are employed to create pores in a variety of shapes and sizes. Although these known techniques may be used in processes of the present invention, they are beyond the scope of the invention. In addition, a wide-range of techniques are available for removing the liquid phase without collapsing the pore structure to form hydrogels, xerogels, aerogels and the like. Again, any of these known methods may be used in present invention but are beyond the scope of the invention.
Likewise, the transition metal dichalcogenides, which comprise at least a portion of the preferred catalyst particles, may be exfoliated from bulk materials by known methods.
Further, once exfoliated their composition may be modified by promoters adsorbed or included between layers by known methods. The intercalation, exfoliation, and composition modification methods of the starting materials are also beyond the scope of this invention.
These preferred exfoliated starting materials may be described as single molecule thick layered materials of the form MX2, where MX~ is a layer-type dichalcogenide (M
_-- Mo, Nb, Ta, Ti, W and V and X ---- S, Se, Te), or the like, exfoliated by intercalation of an alkali metal in a manner such that said alkali metal is substantially intercalated between the layers of the MX2, immersing the intercalated MX~ in a reducible hydrogen generating solution to thereby cause the layers of MX~ to separate and to form a dispersion in the hydrogen generating solution. Other materials that may be induced to form catalytically active particles within the dimension ranges specified in the present invention may also be used. Composition modiFers or promoters may include any described in previous literature. Those most preferred are compounds of Co, Ni, and Fe.
While not wishing to be bound by any particular theory, the present inventors believe that the shape and size of dispersed catalyst particles are important factors in determining the activity and selectivity of the catalyst in a given reaction. What is critical to the present invention is that catalytically active particles of a wide range of materials may be formed within specific dimensional ranges and suspended in immiscible organic liquids.
NANO-DIMENSIONAL SHEETS
According to the present invention, there are provided nano-dimensional sheets suspended in a liquid matrix and methods for producing nano-dimensional sheets of catalytically active layered materials. Said nano-dimensional sheets having:
d) Thickness (z) dimensions between 0.5 and 10 nanometers of the selected catalytically active material, and e) Lengths (x) of between <5 nanometers and up to 100 nanometers, and f) Widths (y) of between <5 nanometers and up to 100 nanometers.
The preferred nano-dimensional sheets are comprised of single molecule thick sheets of the transition metal dichalcogenides suspended in liquids. Said sheets are preferentially comprised of materials having a structure MXZ where M is Mo, Nb, Ta, Ti, W, V
or the like, and X is comprised of S, Se, Te or similar materials. The preferred transition metal dichalcogenides belong to a family of compounds that in the bulk crystalline form have a sheet like structure analogous to graphite, which exhibits strong covalent bonding within the plane and weak Van der Waal's interactions between the sheets. This structure makes it possible to separate the sheets from one another by intercalation of and alkali metal between the sheets of the MX~, immersing the intercalated MXZ in a reducible hydrogen generating solution to thereby cause the layers of MX~ to separate and to form dispersion.
Once separated, the newly created nano-dimensional sheets are stabilized in suspension, with respect to restacking, by molecules of the reducible hydrogen generating solution bound to dangling bonds of the nano-dimensional sheets exposed by the separation of the sheets. Optionally, the reducible hydrogen generating solution used to separate the sheets may continue to be used to suspend the nano-dimensional sheets, or they may be replaced by other protic solvents, miscible aprotic solvents, or immiscible liquids and mixtures of the same.
The process for producing dispersions of said nano-dimensional sheets includes the following steps:
1) Segregating and selecting bulk materials of the form MXZ wherein MXZ is a layer type transition metal dichalcogenide selected from the group consisting of MoSz, TaS2, WS~, on the basis of size. The preferred materials have no dimension greater than 10 microns, and it is most preferred that no dimension of the bulk material exceed 2 microns.
2) Intercalating multi-layer MX~ with an alkali metal in a dry environment for sufficient time to enable the alkali metal to substantially intercalate the layers of the MX2.
3) Immersing the alkali metal intercalated MXZ in a liquid that generates a gas upon reaction with the alkali metal to thereby with suitable agitation cause the layers of MXZ to separate and form a dispersion suspended in the gas generating liquid.
4) Optionally, washing and replenishing, and/or exchanging, and/or modifying the pH of the suspending liquid.
a) Where no particle dimension exceeds 1 micron Finally a method for dispersing said particles in immiscible liquids, such as oil, is disclosed.
DESCRIPTION OF DRAWINGS
Drawing Sheet 1 - Depicts X-ray diffraction methods employed to determine the production the preferred nano-dimensional sheets made from MoS~ into completely exfoliated MoSz is compared with partially exfoliated MoSz and bulk crystalline (unexfoliated) MoSz.
Spectrum (201) exhibits sharp peaks at approximately 28 = 14°, 29°, 33° 39° and 49°
corresponding to the (002), (004), (100), (103) and (105) among other crystal planes.
These peaks are consistent with bulk crystalline MoS2. Exfoliated MoS2 (Spectrum 203) exhibits an asymmetric broadening of the ( 100) plane with a saw-tooth pattern, and has the presence of the ( 110) peak at 58°. Exfoliated MoS2 is also confirmed by the absence of (001) peaks such as the (002) peak at 14°, which would indicate periodicity in the c-axis. Partially exfoliated MoS2 (Spectrum 202) is very similar to that of exfoliated MoS2 except that it exhibits a peak at 14° that indicates stacking of the MoS2 sheets in the c-direction.
DI'awing Sheet 2 - is an illustration of some of the forms of materials of the present invention (301) nano-dimensional sheets, (302) macro-molecular sheets, (303) mesoscopic solid porous structures, (304) three-dimensional semi-solid structures where the lighter circles represent liquid inclusion materials.
Drawing Sheet 3 - is an illustration of the range of orientation of nanodimensional and macro-molecular sheets used to form micro-structures. Number 401 represents nano-dimensional sheets organized to form a microstructure with sheets in a parallel orientation. Number 402 represents various size sheets in a perpendicular orientation forming a porous microstructure. In the figure, the light colored ends correspond to negative charges on the edge sites. Mote that these negative charges will also exist on edges perpendicular to the page where the exfoliated transition dichalcogenide sheet is exposed in this case. The positive charges on the other hand exist on the basal plane and are attracted to the edge sites. The attraction of the basal plane to the edge sites forms the porous organized structure.
Drawing Sheet 4 - depicts a comparison of conversion rates achieved by the products detailed in experiments 4-6.
Drawing Sheet 5 - depicts a comparison of the coke formation achieved by the products detailed in experiments 4-6 DI'aW111g Sheet 6 - depicts a comparison of the sultur removal achieved by the products detailed in experiments 4-6 DI'aW111g Sheet 7 - depicts a comparison of the simulated distillation of the products derived from experiment 4-6 DETAILED DESCRIPTION OF THE INVENTION:
A brief description of sol-gel processes may assist in understanding the techniques disclosed.
For the purposes of this invention the word sol-gel does not describe a product but instead describes a reaction mechanism whereby a sol, which is a colloidal suspension of solid particles in a liquid, transforms into a gel due to the growth and interconnectedness of the solid particles. One theory of the operation of the reaction mechanism is that through continued reactions within the sol, one or more molecules in the sol may eventually reach macroscopic dimensions so that it/they form a solid network that extends substantially throughout the sol. At this point (called the gel point), the substance is said to be a gel. By this definition, a gel is a substance that contains a continuous solid skeleton enclosing a continuous liquid phase. Open-pored solid structures are formed by removing the liquid phase without collapsing the solid skeleton. Techniques, such as inclusions of surfactants, using bacteria as templates, and a wide. variety of other methods are employed to create pores in a variety of shapes and sizes. Although these known techniques may be used in processes of the present invention, they are beyond the scope of the invention. In addition, a wide-range of techniques are available for removing the liquid phase without collapsing the pore structure to form hydrogels, xerogels, aerogels and the like. Again, any of these known methods may be used in present invention but are beyond the scope of the invention.
Likewise, the transition metal dichalcogenides, which comprise at least a portion of the preferred catalyst particles, may be exfoliated from bulk materials by known methods.
Further, once exfoliated their composition may be modified by promoters adsorbed or included between layers by known methods. The intercalation, exfoliation, and composition modification methods of the starting materials are also beyond the scope of this invention.
These preferred exfoliated starting materials may be described as single molecule thick layered materials of the form MX2, where MX~ is a layer-type dichalcogenide (M
_-- Mo, Nb, Ta, Ti, W and V and X ---- S, Se, Te), or the like, exfoliated by intercalation of an alkali metal in a manner such that said alkali metal is substantially intercalated between the layers of the MX2, immersing the intercalated MX~ in a reducible hydrogen generating solution to thereby cause the layers of MX~ to separate and to form a dispersion in the hydrogen generating solution. Other materials that may be induced to form catalytically active particles within the dimension ranges specified in the present invention may also be used. Composition modiFers or promoters may include any described in previous literature. Those most preferred are compounds of Co, Ni, and Fe.
While not wishing to be bound by any particular theory, the present inventors believe that the shape and size of dispersed catalyst particles are important factors in determining the activity and selectivity of the catalyst in a given reaction. What is critical to the present invention is that catalytically active particles of a wide range of materials may be formed within specific dimensional ranges and suspended in immiscible organic liquids.
NANO-DIMENSIONAL SHEETS
According to the present invention, there are provided nano-dimensional sheets suspended in a liquid matrix and methods for producing nano-dimensional sheets of catalytically active layered materials. Said nano-dimensional sheets having:
d) Thickness (z) dimensions between 0.5 and 10 nanometers of the selected catalytically active material, and e) Lengths (x) of between <5 nanometers and up to 100 nanometers, and f) Widths (y) of between <5 nanometers and up to 100 nanometers.
The preferred nano-dimensional sheets are comprised of single molecule thick sheets of the transition metal dichalcogenides suspended in liquids. Said sheets are preferentially comprised of materials having a structure MXZ where M is Mo, Nb, Ta, Ti, W, V
or the like, and X is comprised of S, Se, Te or similar materials. The preferred transition metal dichalcogenides belong to a family of compounds that in the bulk crystalline form have a sheet like structure analogous to graphite, which exhibits strong covalent bonding within the plane and weak Van der Waal's interactions between the sheets. This structure makes it possible to separate the sheets from one another by intercalation of and alkali metal between the sheets of the MX~, immersing the intercalated MXZ in a reducible hydrogen generating solution to thereby cause the layers of MX~ to separate and to form dispersion.
Once separated, the newly created nano-dimensional sheets are stabilized in suspension, with respect to restacking, by molecules of the reducible hydrogen generating solution bound to dangling bonds of the nano-dimensional sheets exposed by the separation of the sheets. Optionally, the reducible hydrogen generating solution used to separate the sheets may continue to be used to suspend the nano-dimensional sheets, or they may be replaced by other protic solvents, miscible aprotic solvents, or immiscible liquids and mixtures of the same.
The process for producing dispersions of said nano-dimensional sheets includes the following steps:
1) Segregating and selecting bulk materials of the form MXZ wherein MXZ is a layer type transition metal dichalcogenide selected from the group consisting of MoSz, TaS2, WS~, on the basis of size. The preferred materials have no dimension greater than 10 microns, and it is most preferred that no dimension of the bulk material exceed 2 microns.
2) Intercalating multi-layer MX~ with an alkali metal in a dry environment for sufficient time to enable the alkali metal to substantially intercalate the layers of the MX2.
3) Immersing the alkali metal intercalated MXZ in a liquid that generates a gas upon reaction with the alkali metal to thereby with suitable agitation cause the layers of MXZ to separate and form a dispersion suspended in the gas generating liquid.
4) Optionally, washing and replenishing, and/or exchanging, and/or modifying the pH of the suspending liquid.
5) Optionally sorting, restacking, drying, re-intercalating, re-exfoliating, and re-suspending the MXZ particles in order to enhance the probability of producing small particles in the x, y dimensions.
6) Aging the suspension for a time and in a manner sufficient to limit the particle growth within the desired range. For nano-dimensional sheets of the preferred MXZ materials suspended in deionized distilled water, at 20C, a time of between minutes and 10 days is preferred.
7) Optionally, adding promoters or compositional modifiers by precipitation, adsorbtion, or inclusions of a substance or substances Y. Preferred Y
materials are elements, hydrides, and compounds and mixtures of the same comprised at least in part of Co, Ni, and Fe.
materials are elements, hydrides, and compounds and mixtures of the same comprised at least in part of Co, Ni, and Fe.
8) Fixing the size of the particles in suspension either by the immediate use of the dispersion as a catalyst or by dispersing the particles in an immiscible organic liquid, preferably neat oil.
Although we do not wish to be bound by any theory, the following describes a possible explanation of the control of the nano-dimensional sheet size of the exfoliated transition metal dichalcogenides in suspension;
The length and width of the nano-dimensional sheets of exfoliated material may be partially determined by the initial particle size of the bulk material prior to exfoliation.
This is caused by the strong covalent bonding of the M and XZ atoms in the plane as opposed to the weak Van der Waal's X to X interactions between the sheets that allow the sheets to be separated. It is thought that the sheets tend resist breaking within the plane, with the exception of crystalline faults that may be present or created, thus weakening the bonds within the plane and allowing some cracking or breaking of the sheets themselves. Therefore, it is thought that there exists a range of sheet sizes in suspension based on original sheet size within the bulk structure. Thus exfoliated MXZ
prepared from bulk materials composed of small particle sizes will result in particles in a suspension with smaller length and width dimensions than exfoliated materials prepared from bulk materials selected prior to exfoliation for their larger dimensions.
However, the range of length and width dimensions measured by the inventors, no mataer how large the dimensions of the bulk material prior to exfoliation (provided that the bulk material was selected from the preferred group of materials), never exceeded nanometers within a time frame of up to 3 days after exfoliation. Others have reported sheet sizes up to 100 nanometers but have not indicated any correlation between the sheet size and the aging time of the suspended materials. As the bulk material was initially composed of sheets with considerably larger size than 100 nanometers, this would indicate that at least some of the bulk materials used by others may have been composed of particles larger or of larger crystalline faults than those found by the present inventors.
Thus an initial segregating and selection step has been included in the process.
Further experimentation has shown that standard sorting techniques such as sieving, centrifuging, settling, etc., may be applied to separate either dried or suspended sheets with smaller length (x) and width (y) dimensions from those with larger x, y, dimensions.
Experiments to determine the catalytic activity of said nano-dimensional sheets were conducted using both pure MXz materials and MX~Y materials where Y was a soluble metal hydride. The experiments indicated a significantly better performance by the materials of the present invention than by a commercial reference catalyst.
MACRO-MOLECULAR SHEETS
According to the present invention, there are provided macro-molecular sheets suspended ina liquid matrix and methods for producing macro-molecular sheets of catalytically active layered materials. Said macro-molecular sheets having:
I . A thickness (z) dimension between 1 and 100 manometers, and 2. Lengths (x) of between 100 manometers and 150 microns, and 3. Widths (y) of between 100 manometers and 150 microns of the selected catalytically active material.
The methods for inducing namo-dimensional sheets described previously to assemble into micro-sheets comprise suspending said namo-dimensional sheets for predetermined periods of time in liquid mediums selected on the basis of their polarity, viscosity, pH
value, and ability to act as templates upon which the micro-sheets may form.
In other words the inventors have discovered that the x, y, dimensions of the sheets can be controlled, within a range, while maintaining the z dimension by: the selection of the suspension medium - for example, whether it is water or alcohol, etc., the condition of the suspension medium - for example whether it is alkaline or acidic and to the degree of alkalinity or acidity, the compatibility of combinations of suspension mediums -- for example whether a mixture of miscible and immiscible materials are selected as suspension medium, such as water and oil etc., or a mixture where one suspension medium is a solvent for the other, as in combinations of dimethylformamide and styrene etc., the molecular structure of the suspension medium - for example namo-sheets will organize into macro-molecular of larger dimensions in a shorter period of time when suspended in mediums comprised of larger size molecules, and finally, the assembly of macro-molecular sheets from nano-sheets is a function of time where sheets that can be induced to remain suspended for longer periods of time assemble into larger micro-sheets.
The selection of suspension medium appears to determine the eventual size and stability of the micro-sheets with water at Ph 7 in the mid-range providing stable macro-molecular sheets of maximum length, width, dimensions of approximately 100 microns after five months time, and suspensions in mixtures of both miscible and immiscible organic material having a similar viscosity to water, generating sheet sizes of up to 150 micron in length after aging for approximately two years. The size and shape of the macro-molecular sheets may also be effected by the viscosity of the suspension medium.
MACRO-MOLECULAR SHEET PROCESS
Process steps for producing macro-molecular dispersions are described more concisely below;
I ) Intercalating mufti-layer MX~ with an alkali metal in a dry environment for sufficient time to enable the alkali metal to substantially intercalate the layers of the MXz.
2) Immersing the alkali metal intercalated MXZ in a liquid that generates a gas upon reaction with the alkali metal to thereby with suitable agitation cause the layers of MXZ to separate and form a dispersion suspended in the gas generating liquid.
3) Optionally, washing and replenishing, and/or exchanging, and/or modifying the pH of the suspending liquid.
4) Aging the suspension for a time and in a manner sufficient to limit the particle growth within the desired range. For nano-dimensional sheets of the preferred MXz materials suspended in deionized distilled water, at 20C, a time of between days and 5 months is preferred. Larger sheets may require longer times.
However, in all cases the growth of the sheets must be stopped before the gel point is reached.
5) Optionally, adding promoters or compositional modifiers by precipitation, adsorbtion, or inclusions of a substance or substances Y. Preferred Y
materials are elements, hydrides, and compounds and mixtures of the same comprised at least in part of Co, Ni, and Fe.
6) Fixing the size of the particles in suspension either by the immediate use of the dispersion as a catalyst or by dispersing the particles in immiscible organic liquids, preferably neat oil.
MESOSCOPIC STRUCTURES
According to the present invention, there are provided mesoscopic structures suspended in a liquid matrix and methods for producing mesoscopic structures of catalytically active layered materials. Said mesoscopic structures having:
a) No dimension grater than 1 micron ASSEMBLING NANO AND MACRO-SHEETS INTO MESOSCOPIC
STRUCTURES:
Highly oriented nano-dimensional and micro-dimensional sheets of MXz can also be formed into semi-solid microstructures by inducing MXz to move to the interface between a polar material (e.g. water, or the like) and a non-polar material (e.g. hexane, or the tike). In this case, the OH- ions bound to the surface of the sheets are replaced with the non-polar organic molecule. This renders the basal plane non-polar, while the stronger M-OH interaction remains intact. Therefore the new structure consists of polar edges but non-polar basal planes. The non-polar portion of the sheets becomes attracted to the non-polar structure of other sheets, which results in an ordered configuration of sheets stacked together separated by minimum of a non-polar organic bi-layer.
These new semi-solid structures may then be mixed with other organic materials with higher boiling points than the polar molecules and heated to evolve the polar material. Semi-solid structures of this type have proven to be highly active as dispersed catalyst.
Further, methods have been discovered for adjusting and fixing the orientation of both nano-sheets and micro-sheets in three dimensions to create solid porous structures with tunable pore sizes.
Pore size in solid structures is of critical importance in many areas of catalysis, where micro-porous structures are suitable for one type of feedstock and macro-porous structures are need for a different feedstock. Flow rate of a feedstock through a reactor is also a critical factor in the economic operation of refining and chemical processes. T'he quantity (volume) of catalyst required as well as the catalyst size and shape can significantly effect the flow rate in a reactor. Typically, the minimum quantity of catalyst required to complete a given reaction within a given time is the balance point in determining the economics of a process. Today the major component, ~80% by weight, of most petroleum catalysts are comprised of inert filler material whose major purpose is to form a mechanically stable, porous structure on which the active catalyst material may be supported. The inventors believe that it would be more beneficial to use the catalytically active material to form the major structural component of the catalyst, and have devised methods for assembling nano-dimensional and micro-dimensional sheets of catalytically active material into structurally stable solid forms with inclusions of various promoter materials and tunable pore sizes.
Structures can be fixed in place by techniques such as freeze drying, and heating for times and at temperatures sufficient evolve any liquids trapped between sheets and in atmospheres designed to protect the catalytic material from conversion or to convert a promoter material into the form desired. The fixing techniques may be used individually or in combination. Heat treatments in selected atmospheres to burnout inclusion templates and/or exposure of the microstructure to chemicals such as acids or alkalis can also be used to dissolve inclusion templates.
ORIENTATION OF MICRO-SHEETS
Micro-sheets based on exfoliated transition metal dichalcogenides can be molded into solid forms with inclusions of promoter materials such as nickel, cobalt, and others known to be beneficial to catalysis. The orientation of the sheets within a range between parallel and perpendicular can be controlled by the pH of the suspension. For example, the single molecule thick sheets will align themselves in parallel when the pH
of the suspension is greater than the point of zero charge (PZC) which is at approximately 2.0 ~
0.05. On the other hand, the single layers can be attached together in the form of edge to basal planes, producing a low-density material with a "house of cards" (HOC) struchire where the basal planes repel each other. This is prepared by dropping the pH
of the suspension to the PZC. This structure arises because the edges of the exfoliated transition metal dichalcogenides are of opposite charge to the basal plane.
Although methods like those above have been described in the past to adjust the orientation of nano-dimensional sheets, the present disclosure revels for the first time the surprising ability to employ techniques to adjust the void spaces or pore sizes of microstructures comprised of macro- molecular sheets and combinations of nano and macro sheets.
As reported above, collections of macro-sheets may be induced to orient themselves with respect to one another, within ranges between the parallel and the perpendicular, to create microstructures of actively catalytic materials, with or with out inclusions of promoter materials. Said inclusions may be used to maintain the orientation and spacing of the sheets and may also be useful at facilitating reactions beneficial to the refining of petroleum and other products. For example, adding acids such as nitric acid to suspensions of micro-sheets in water will cause a significant portion of the sheets to orient themselves perpendicular to other sheets in the suspension.
Alternatively, immiscible organic liquids or mixtures of immiscible may be utilized to displace the protic solvents or miscible aprotic solvents used to initially support the nano-dimensional sheets.
FORMING MICRO-STRUCTURES INTO MACRO-STRUCTURES:
Finally, the inventors have discovered that the microstructures described above may be molded into larger shapes by coating templates such as green-forms that may be dissolved or burnt out after the basic microstructures has been formed.
Alternatively, binders such as clays or other binders suitable to the conditions of use, may be mixed with the microstructures and extruded into shapes. However in all cases of the present invention the porous materials formed must fractured into mesoscopic dimensions prior to its dispersion in the support matrix.
MESOSCOPIC STRUCTURE PROCESS
Processes for producing the mesoporous particles in suspension are described below;
1 ) Segregating and selecting bulk materials of the form MXZ wherein MXz is a layer type transition metal dichalcogenide selected from the group consisting of MoS2, TaSZ, WS2, on the basis of size. The preferred materials have no dimension greater than 10 microns, and it is most preferred that no dimension of the bulk material exceed 2 microns.
2) Intercalating multi-layer MXZ with an alkali metal in a dry environment for sufficient time to enable the alkali metal to substantially intercalate the layers of the MX2.
3) Immersing the alkali metal intercalated MXZ in a liquid that generates a gas upon reaction with the alkali metal to thereby with suitable agitation cause the layers of MXZ to separate and form a dispersion suspended in the gas generating liquid.
4) Optionally, washing and replenishing, and/or exchanging, and/or modifying the pH of the suspending liquid.
5) Optionally sorting, restacking, drying, re-intercalating, re-exfoliating, and re-suspending the MX~ particles in order to enhance the probability of producing small particles in the x, y dimensions.
6) Aging the suspension for a time and in a manner sufficient to limit the particle growth within the desired range. Preferably the particles will be allowed to reach the gel point.
7) Optionally, adding promoters or compositional modifiers by precipitation, adsorbtion, or inclusions of a substance or substances Y. Preferred Y
materials are elements, hydrides, and compounds and mixtures of the same comprised at least in part of Co, Ni, and Fe.
8) Separating the particles from the dispersing liquid 9) Drying the particles in a manner such that the particles form a solid porous structure.
Although we do not wish to be bound by any theory, the following describes a possible explanation of the control of the nano-dimensional sheet size of the exfoliated transition metal dichalcogenides in suspension;
The length and width of the nano-dimensional sheets of exfoliated material may be partially determined by the initial particle size of the bulk material prior to exfoliation.
This is caused by the strong covalent bonding of the M and XZ atoms in the plane as opposed to the weak Van der Waal's X to X interactions between the sheets that allow the sheets to be separated. It is thought that the sheets tend resist breaking within the plane, with the exception of crystalline faults that may be present or created, thus weakening the bonds within the plane and allowing some cracking or breaking of the sheets themselves. Therefore, it is thought that there exists a range of sheet sizes in suspension based on original sheet size within the bulk structure. Thus exfoliated MXZ
prepared from bulk materials composed of small particle sizes will result in particles in a suspension with smaller length and width dimensions than exfoliated materials prepared from bulk materials selected prior to exfoliation for their larger dimensions.
However, the range of length and width dimensions measured by the inventors, no mataer how large the dimensions of the bulk material prior to exfoliation (provided that the bulk material was selected from the preferred group of materials), never exceeded nanometers within a time frame of up to 3 days after exfoliation. Others have reported sheet sizes up to 100 nanometers but have not indicated any correlation between the sheet size and the aging time of the suspended materials. As the bulk material was initially composed of sheets with considerably larger size than 100 nanometers, this would indicate that at least some of the bulk materials used by others may have been composed of particles larger or of larger crystalline faults than those found by the present inventors.
Thus an initial segregating and selection step has been included in the process.
Further experimentation has shown that standard sorting techniques such as sieving, centrifuging, settling, etc., may be applied to separate either dried or suspended sheets with smaller length (x) and width (y) dimensions from those with larger x, y, dimensions.
Experiments to determine the catalytic activity of said nano-dimensional sheets were conducted using both pure MXz materials and MX~Y materials where Y was a soluble metal hydride. The experiments indicated a significantly better performance by the materials of the present invention than by a commercial reference catalyst.
MACRO-MOLECULAR SHEETS
According to the present invention, there are provided macro-molecular sheets suspended ina liquid matrix and methods for producing macro-molecular sheets of catalytically active layered materials. Said macro-molecular sheets having:
I . A thickness (z) dimension between 1 and 100 manometers, and 2. Lengths (x) of between 100 manometers and 150 microns, and 3. Widths (y) of between 100 manometers and 150 microns of the selected catalytically active material.
The methods for inducing namo-dimensional sheets described previously to assemble into micro-sheets comprise suspending said namo-dimensional sheets for predetermined periods of time in liquid mediums selected on the basis of their polarity, viscosity, pH
value, and ability to act as templates upon which the micro-sheets may form.
In other words the inventors have discovered that the x, y, dimensions of the sheets can be controlled, within a range, while maintaining the z dimension by: the selection of the suspension medium - for example, whether it is water or alcohol, etc., the condition of the suspension medium - for example whether it is alkaline or acidic and to the degree of alkalinity or acidity, the compatibility of combinations of suspension mediums -- for example whether a mixture of miscible and immiscible materials are selected as suspension medium, such as water and oil etc., or a mixture where one suspension medium is a solvent for the other, as in combinations of dimethylformamide and styrene etc., the molecular structure of the suspension medium - for example namo-sheets will organize into macro-molecular of larger dimensions in a shorter period of time when suspended in mediums comprised of larger size molecules, and finally, the assembly of macro-molecular sheets from nano-sheets is a function of time where sheets that can be induced to remain suspended for longer periods of time assemble into larger micro-sheets.
The selection of suspension medium appears to determine the eventual size and stability of the micro-sheets with water at Ph 7 in the mid-range providing stable macro-molecular sheets of maximum length, width, dimensions of approximately 100 microns after five months time, and suspensions in mixtures of both miscible and immiscible organic material having a similar viscosity to water, generating sheet sizes of up to 150 micron in length after aging for approximately two years. The size and shape of the macro-molecular sheets may also be effected by the viscosity of the suspension medium.
MACRO-MOLECULAR SHEET PROCESS
Process steps for producing macro-molecular dispersions are described more concisely below;
I ) Intercalating mufti-layer MX~ with an alkali metal in a dry environment for sufficient time to enable the alkali metal to substantially intercalate the layers of the MXz.
2) Immersing the alkali metal intercalated MXZ in a liquid that generates a gas upon reaction with the alkali metal to thereby with suitable agitation cause the layers of MXZ to separate and form a dispersion suspended in the gas generating liquid.
3) Optionally, washing and replenishing, and/or exchanging, and/or modifying the pH of the suspending liquid.
4) Aging the suspension for a time and in a manner sufficient to limit the particle growth within the desired range. For nano-dimensional sheets of the preferred MXz materials suspended in deionized distilled water, at 20C, a time of between days and 5 months is preferred. Larger sheets may require longer times.
However, in all cases the growth of the sheets must be stopped before the gel point is reached.
5) Optionally, adding promoters or compositional modifiers by precipitation, adsorbtion, or inclusions of a substance or substances Y. Preferred Y
materials are elements, hydrides, and compounds and mixtures of the same comprised at least in part of Co, Ni, and Fe.
6) Fixing the size of the particles in suspension either by the immediate use of the dispersion as a catalyst or by dispersing the particles in immiscible organic liquids, preferably neat oil.
MESOSCOPIC STRUCTURES
According to the present invention, there are provided mesoscopic structures suspended in a liquid matrix and methods for producing mesoscopic structures of catalytically active layered materials. Said mesoscopic structures having:
a) No dimension grater than 1 micron ASSEMBLING NANO AND MACRO-SHEETS INTO MESOSCOPIC
STRUCTURES:
Highly oriented nano-dimensional and micro-dimensional sheets of MXz can also be formed into semi-solid microstructures by inducing MXz to move to the interface between a polar material (e.g. water, or the like) and a non-polar material (e.g. hexane, or the tike). In this case, the OH- ions bound to the surface of the sheets are replaced with the non-polar organic molecule. This renders the basal plane non-polar, while the stronger M-OH interaction remains intact. Therefore the new structure consists of polar edges but non-polar basal planes. The non-polar portion of the sheets becomes attracted to the non-polar structure of other sheets, which results in an ordered configuration of sheets stacked together separated by minimum of a non-polar organic bi-layer.
These new semi-solid structures may then be mixed with other organic materials with higher boiling points than the polar molecules and heated to evolve the polar material. Semi-solid structures of this type have proven to be highly active as dispersed catalyst.
Further, methods have been discovered for adjusting and fixing the orientation of both nano-sheets and micro-sheets in three dimensions to create solid porous structures with tunable pore sizes.
Pore size in solid structures is of critical importance in many areas of catalysis, where micro-porous structures are suitable for one type of feedstock and macro-porous structures are need for a different feedstock. Flow rate of a feedstock through a reactor is also a critical factor in the economic operation of refining and chemical processes. T'he quantity (volume) of catalyst required as well as the catalyst size and shape can significantly effect the flow rate in a reactor. Typically, the minimum quantity of catalyst required to complete a given reaction within a given time is the balance point in determining the economics of a process. Today the major component, ~80% by weight, of most petroleum catalysts are comprised of inert filler material whose major purpose is to form a mechanically stable, porous structure on which the active catalyst material may be supported. The inventors believe that it would be more beneficial to use the catalytically active material to form the major structural component of the catalyst, and have devised methods for assembling nano-dimensional and micro-dimensional sheets of catalytically active material into structurally stable solid forms with inclusions of various promoter materials and tunable pore sizes.
Structures can be fixed in place by techniques such as freeze drying, and heating for times and at temperatures sufficient evolve any liquids trapped between sheets and in atmospheres designed to protect the catalytic material from conversion or to convert a promoter material into the form desired. The fixing techniques may be used individually or in combination. Heat treatments in selected atmospheres to burnout inclusion templates and/or exposure of the microstructure to chemicals such as acids or alkalis can also be used to dissolve inclusion templates.
ORIENTATION OF MICRO-SHEETS
Micro-sheets based on exfoliated transition metal dichalcogenides can be molded into solid forms with inclusions of promoter materials such as nickel, cobalt, and others known to be beneficial to catalysis. The orientation of the sheets within a range between parallel and perpendicular can be controlled by the pH of the suspension. For example, the single molecule thick sheets will align themselves in parallel when the pH
of the suspension is greater than the point of zero charge (PZC) which is at approximately 2.0 ~
0.05. On the other hand, the single layers can be attached together in the form of edge to basal planes, producing a low-density material with a "house of cards" (HOC) struchire where the basal planes repel each other. This is prepared by dropping the pH
of the suspension to the PZC. This structure arises because the edges of the exfoliated transition metal dichalcogenides are of opposite charge to the basal plane.
Although methods like those above have been described in the past to adjust the orientation of nano-dimensional sheets, the present disclosure revels for the first time the surprising ability to employ techniques to adjust the void spaces or pore sizes of microstructures comprised of macro- molecular sheets and combinations of nano and macro sheets.
As reported above, collections of macro-sheets may be induced to orient themselves with respect to one another, within ranges between the parallel and the perpendicular, to create microstructures of actively catalytic materials, with or with out inclusions of promoter materials. Said inclusions may be used to maintain the orientation and spacing of the sheets and may also be useful at facilitating reactions beneficial to the refining of petroleum and other products. For example, adding acids such as nitric acid to suspensions of micro-sheets in water will cause a significant portion of the sheets to orient themselves perpendicular to other sheets in the suspension.
Alternatively, immiscible organic liquids or mixtures of immiscible may be utilized to displace the protic solvents or miscible aprotic solvents used to initially support the nano-dimensional sheets.
FORMING MICRO-STRUCTURES INTO MACRO-STRUCTURES:
Finally, the inventors have discovered that the microstructures described above may be molded into larger shapes by coating templates such as green-forms that may be dissolved or burnt out after the basic microstructures has been formed.
Alternatively, binders such as clays or other binders suitable to the conditions of use, may be mixed with the microstructures and extruded into shapes. However in all cases of the present invention the porous materials formed must fractured into mesoscopic dimensions prior to its dispersion in the support matrix.
MESOSCOPIC STRUCTURE PROCESS
Processes for producing the mesoporous particles in suspension are described below;
1 ) Segregating and selecting bulk materials of the form MXZ wherein MXz is a layer type transition metal dichalcogenide selected from the group consisting of MoS2, TaSZ, WS2, on the basis of size. The preferred materials have no dimension greater than 10 microns, and it is most preferred that no dimension of the bulk material exceed 2 microns.
2) Intercalating multi-layer MXZ with an alkali metal in a dry environment for sufficient time to enable the alkali metal to substantially intercalate the layers of the MX2.
3) Immersing the alkali metal intercalated MXZ in a liquid that generates a gas upon reaction with the alkali metal to thereby with suitable agitation cause the layers of MXZ to separate and form a dispersion suspended in the gas generating liquid.
4) Optionally, washing and replenishing, and/or exchanging, and/or modifying the pH of the suspending liquid.
5) Optionally sorting, restacking, drying, re-intercalating, re-exfoliating, and re-suspending the MX~ particles in order to enhance the probability of producing small particles in the x, y dimensions.
6) Aging the suspension for a time and in a manner sufficient to limit the particle growth within the desired range. Preferably the particles will be allowed to reach the gel point.
7) Optionally, adding promoters or compositional modifiers by precipitation, adsorbtion, or inclusions of a substance or substances Y. Preferred Y
materials are elements, hydrides, and compounds and mixtures of the same comprised at least in part of Co, Ni, and Fe.
8) Separating the particles from the dispersing liquid 9) Drying the particles in a manner such that the particles form a solid porous structure.
10) Intercalating the thus formed porous structure with an alkali metal in a dry environment.
1 1 ) Immersing the alkali metal intercalated structure in a liquid that generates a gas upon reaction with the alkali metal to thereby with suitable agitation cause the porous structure to fracture into mesoscopic dimensioned particles 12) Separating mesoseopic particles from larger particles through sedimentation, centrifuging or other known methods.
13 ) Dispersing said mesoscopic particles in a liquid matrix, preferably neat oil.
PROCESS FOR DISPERSING EXFOLIATED PARTICLES IN IMMISCIBLE
LIQUIDS
The inventors have found that it is beneficial in many cases to transfer dispersions of catalytically active materials from suspensions in water to suspensions in oils that are substantially free of water. A process for accomplishing said transfer is described below;
1 ) Initially preparing a dispersion of exfoliated transition metal dichalcogenides in water 2) Adding the desired transfer oil to the dispersion.
3) Optionally adjusting the pH of the water to less than pH7 in order to cause the exfoliated material to from at the oil/water interface.
4) Adding a surfactant to the combined oil/water composition. Preferably a cationic surfactant is used to drive the exfoliated materials further into the oil.
5) Decanting the oil and exfoliated material dispersion 6) Separating the surfactant and remaining water form the decanted oil/exfoliated material dispersion by centrifuging or settling.
As can be readily seen by one skilled in the art the order of these and previously described process steps may be modified without departing from the scope or spirit of the invention.
EXPERIMENTS
Methods employed by the present inventors to determine particle dimensions in all of the experiments disclosed include one or more of the following, direct microscopic observation, filtration, calculation of sedimentation rates by the formula;
Sedimentation rate dx/dt = [(4nr3/3)( p'-p)g]6~rt~
_ [2r2(p'-p)g~/9r1 where ~ = viscosity of surrounding medium p = density of surrounding medium p'= density of colloidal particle material r =- radius of colloidal particle Measurment of (z) dimension was by x-ray diffraction and measurement of (x) and (y) dimensions was by x-ray diffraction and calculation using the Scherrer equation.
Experiment 1 Methods for forming nano-sheets into macro-sheets Example 1 A 10 kg sample of exfoliated transition metal dichalcogenide was produced by standard methods. Immediately after the exfoliation and washing, the material was examined by x-ray diffraction and the single molecule thick sheet structure with (x) and (y) dimensions less than 100 manometers was confirmed. A 250 ml portion of the sample containing 20 mg /ml of exfoliated material in Ph 7 water was filtered through a 1 micron filter and allowed to sit undisturbed in a sealed jar at approximately 23C for three months. After the three month period the contents of the jar were again filtered at I micron and it was noted that the majority of the exfoliated material would not pass through the filter. A sample of the material retained by the filter was examined by x-ray diffraction and the single molecule thick structure was again confirmed.
Various samples were examined where the suspension medium and/or pH conditions of the water was adjusted within a range between Ph2 to Ph 14, and the age of the samples was adjusted from 1 week to 3 years. Micro-sheets having a single molecule thickness and with length and/or breadth measurements in excess of 150 microns were produced.
Example 2 Electrical conductivity tests on exfoliated transition metal dichalcogenides contained at the interface between water and immiscible organic solvents such as methylmethacrylate monomer demonstrate that namo-sheets can be induced to organize into parallel micro-sheets rapidly by using the organic molecules as templates. The speed of the micro-sheet formation may be monitored by a measurement of the increase in conductivity.
Exfoliated transition metal dichalcogenide was prepared by standard methods.
0.3 ml of methylmethacrylate (MMA) was added to the exfoliated suspension containing 0.5 g of exfoliated transition metal dichalcogenide.
Upon addition of MMA to the exfoliated transition metal dichalcogenide suspension and shaking, it was observed that the exfoliated material moves toward the water/MMA
interface.
Electrical conductivity measurements were taken using a two-point probe with a fixed separation of 13.5 mm between the probes. It was observed that the conductivity of the exfoliated transition metal dichalcogenide/MMA mixture increased over time by a factor of 10 times the conductivity on day 2.
SampleElapsed 2 days ~ 12 days ~ 22 days 35 days Time 4 0.21-0.22 1.22-1.30 I 20 ml + 0.10-0. I 2 j 0.30-0.
3 ml 0 MM ~
A
Experiment 2 Orientation of micro-sheets to form solid structures with selectable pore sizes:
Example 1 - parallel orientation with freeze dry fixing An aged exfoliated transition metal dichalcogenide, (MoS2) was dispersed in water containing 2wt% glucose polymers, where in addition to glucose the composition includes, per 100 grams, not more than 30mg calcium, l lOmg sodium, l Omg potassium, 223mg chloride, and Smg phosphorous. The samples centrifuged to create a paste and then freeze-dried. Once dry, a portion of the solid freeze-dried sample was re-suspended in the original solvents and examined by X-ray diffraction along with its control.
The results of the X-ray showed that the freeze-dried sample had the same characteristic pattern indicating single molecule thick sheets as the control sample, thus indicating that the parallel oriented single molecule structure had been maintained in the resulting solid. A portion of the freeze-dried sample was heated under controlled atmosphere to evolve the inclusion and generate a micro-porous structure.
Example 2 - perpendicular orientation with different size sheets and heat fixing Two 250 ml samples of exfoliated MoS~ were prepared by standard techniques and dispersed in water (water suspension, 2.1% exfoliated material). One sample labeled DMC024 had been aged for 2 months in neutral pH water, the other labeled DMC006 was freshly made.
Approximately 500 ml HNO, solution (pH 1.82) was added drop-wise to each of the suspensions and stirred.
- The pH of the samples were adjusted the by adding more HN03 solution in small amounts to reach a pH of 1.97. Sowing and pH control was maintained for ~ 15 minutes and then solids were allowed settle. Both suspensions cleared rapidly.
The solids were retained separately with a vacuum filter through #2 filter paper. A large volume of paste is collected. Next the solids were rinsed with ~50 ml water The samples were dried in a tube furnace for 2 hours under flowing argon at and then at SOOC for 3 hours under hydrogen to create a solid porous structure. As can be seen from the table below, the sample made from older, larger, sheets had distinctly different surface area and pore sizes than the fresh exfoliated material.
1. Surface areas:
Sample Surface area, Pore volume, m2/g cm3/g DMC006 46.1 0.12 DMC024 23.6 (1.087 Experiment 3 Forming mesoscopic strucutures:
The materials produced in experiment 2 above were immersed in 2.5 molar n-butylithium in hexane for 72 hours in a dry environment. The resulting alkali metal intercalated porous structure was immersed in water. Copious quantities of gas and significant heat was generated. The porous structure was fractured smaller particles.
Particles were segregated by size through sedimentation and those in the mesoscopic range were dispersed in neat oil forming a dispersion.
Experiment 4 Catalysis using nano-sheets:
This slurry hydrocracking reaction involved the use of nano-dimensional sheets of MoS2 applied as a catalyst to upgrade Suncor, Athabasca bitumen. The sample in this case was 3 days old before use. Dimensions were shown to be approximately 6.2 angstroms in thickness (z dimension) by x-ray diffraction and less than I micron in any dimension by filtration and less than 100 nanometers in any dimension by x-ray diffraction.
a) Preparation of nano-dimensional MoS~ -g of MoS2 (Aldrich) with particle sizes of 2 microns or less was intercalated with SO ml 2.S M n-BuLi solution in hexane (Aldrich). After a minimum of 72 hours, the excess of n-BuLi and hexane was decanted and distilled water was added for the exfoliation of the MoS2. The paste reacted vigorously with the water and gases evolved. Exfoliation was completed by sonicating the mixture for 30 minutes.
'The paste was washed with water, stirred for 30 minutes, centrifuged for 30 minutes at 3000 rpm. The water was decanted and replenished with deionized distilled water and the exfoliated material was resuspended. This wash/centrifuge/decant/
resuspension cycle was repeated twice, until the pH was neutral.
b) Materials characteristics:
Feedstock - Suncor Athabasca bitumen This bitumen is the feed to a delayed coker after hot water extraction, dewatering and naphtha recovery. Relevant properties of this feed are as follows:
Carbon (wt%) 84.03 Hydrogen (wt%) 9.89 Nitrogen (wt%) 0.41 Sulfur (wt%) 4.91 Density @ 15.6C 1.016 Aromaticity, C 13 0.33 Simulated Distillation C, (wt%) IBP - 200C 0.75 200 - 343 C 10.11 343 - 525 C 35.94 525+ C 53.20 Nano-Dimensional Exfoliated MoSz (TDM - O1) -Sample Name TDM-O1 Suspension solvent: Water MoS2 concentration: 22 mg/ml Age: 3 days pH: 7.39 c) Autoclave test - An Autoclave Engineers Inc. 3165S 1 L CSTR (continuously stirred tank reactor) rated at MAWP 5325 psig @ 510°C was used as the reaction vessel for the batch slurry tests. The conditions selected for these scoping tests were 430°C reaction temperature and 60 minute residence time. The charge hydrogen pressure was 800 psig at room temperature to obtain an operating pressure at temperature of 1500 psig. The reaction mixture was stirred at 1000 rpm. The test conditions were selected to provide measurable hydrocracking conversion of a heavy oil. A blank thermal run was done with the same parameters except for the addition of a catalyst.. Test conditions were as follows:
Pressure:800 psig hydrogen (initial pressure at room temperature) Temperature:430C
Time: 60 min Feed: 400 g Catalyst:1000 ppmw (based upon molybdenum content) Stirrer:1000 rpm The clean reactor was charged with approximately 200 g of the feed and then the catalyst suspension was weighed into the reactor. The remaining feed portion was then charged with a target content of 1000 ppmw molybdenum. After flushing the reactor gas head-space three times with nitrogen, the receiver condenser was cooled in an ice/water bath at 0°C. The water from the TDM-water suspension was then removed at 120°C under a nitrogen flow of 400 mL/min with constant stirring at 1000rpm. The water was collected and weighed until complete removal.
The reactor was flushed with hydrogen three times and then the system was pressurised to 800 psig. The internal temperature was raised to 430°C
with constant stirring at 1000 rpm. An internal cooling coil was employed to maintain the operating temperature within +i- 2°C of the target temperature. At the 60-min residence time the heaters were turned off, cooling water flow was initiated, and the reactor insulation was removed to return the reactor to room temperature.
Once the system was at room temperature, the reactor gas was slowly discharged through the condensers. A gas sample was obtained in a Teflon-lined gas sampling bag (Calibrated Instruments, New York) for subsequent analysis.
Reactor liquids were collected and pressure filtered to obtain a neat filtered product oil. The reactor was washed with tetrahydrofuran. This solvent was collected, pressure filtered then removed by a rotary evaporator. The oil product remaining was added to the product liquid. Collected reactor solids were dried in a vacuum oven at 100°C. Cleaning towels were used to recover mostly oil liquids collected throughout the clean-up and were recorded as losses.
The recovered liquid mass was determined and a combined product oil (neat filtered product oil plus condensate) mixture obtained. This sample was tested for density, sulfur content and simulated distillation analyses. The results of the analysis are included in DRAWING SHEETS 4 through 7 as (TDM -Ol ). From these results it is clear that nano-dimensional sheets are more active in the catalysis of this feedstock than molybdenum napthenate.
Experiment 5 Catalysis using nano-sheets with promoters:
This slurry hydrocracking reaction involved the use of~ an inclusion of a soluble magnesium hydride inclusion between nano-sheets of exfoliated MoS2 as the catalyst for the hydro-conversion of Suncor, Athabasca bitumen.
a) Preparation of exfoliated MoSz followed the same procedure and aging described in experiment 2. After the third wash, the TDM was washed twice with DMF for water removal and with tetrahydrofuran (THF 99.5%, inhibited with 0.025%
BHT), and finally resuspended in THF. The suspension had a concentration of 34 mg/ml of exfoliated MoS2. The soluble magnesium hydride was prepared by known methods, starting with dioctylmagnesium as the dialkylmagnesium precursor. Lastly, the MgH2 was included between sheets of the exfoliated MoS2 to form a microstructure with a parallel sheet orientation.
b) Materials characteristics:
Suncor Athabasca bitumen: See Example 1b).
Catalyst sample TDM-metal hydride suspension:
Sample Name TDM-03 Suspension solvent:THF
Mo concentration 2.58 (w/w '%):
Mg concentration 0.54 (w/w%) Impurities (w/w%) 2.18 Age: 3 days The tetrahydrofuran suspension was removed at 80°C under a gas flow for 2 hours. Little tetrahydrofuran was collected at the condenser and it appears that this solvent was flushed out by nitrogen gas flow.
c) The Autoclave test - The procedure was as described in example 1 and 2.
Amounts used: 406.58 g of bitumen, 576 ppm Mo.
The results of the analysis are included in DRAWING SHEETS 4 through ? as (TDM
-03). From these results it is clear that the addition of an inclusion material, within parallel oriented sheets, can be useful in modifying the reaction. In this case the inclusion produced a semi-solid microstructure that was more active in the catalysis of this feedstock than molybdenum napthanate.
Experiment 6 Catalysis using macro-sheets:
Macro-sheets of exfoliated single layer MoS2 (TDM-02), employed in this slurry hydrocracking reaction involved the use of macro-sheets, comprised of sheets having length and width dimensions in a range from less than 1 micron to sheets exceeding 45 microns and depth measurements of approximately 6.2 angstroms, to upgrade SL111COr, Athabasca bitumen. The length and width measurements were determined by filtration, depth dimensions were determined by x-ray diffraction. The sample (TDM - 02) was aged 5 weeks suspended in neutral pH water before use.
c) Preparation of single layer MoS2 (TDM - 02) - 10 g of MoS2 (Aldrich) was intercalated with 50 ml 2.5 M n-BuLi solution in hexane (Aldrich). After a minimum of 72 hours, the excess of n-BuLi and hexane was decanted and distilled water was added for the exfoliation of the MoSz. The paste reacted vigorously with the water and gases evolved. Exfoliation was completed by sonicating the mixture for 30 minutes. The paste was washed with water, stirred for 30 minutes, centrifuged for 30 minutes at 3000 rpm and decanted. This wash/centrifuge/decant cycle was repeated twice, until the pH was neutral.
d) Materials characteristics:
Feedstock - Suncor Athabasca bitumen This bitumen is the feed to a delayed coker after hot water extraction, dewatering and naphtha recovery.
Macro-sheets of exfoliated MoSZ (TDM-02) -Sample Name TDM-02 Suspension solvent:Water MoS~ concentration:22 mg/ml Age: 5 weeks PH: 7.39 Autoclave test - An Autoclave Engineers Inc. 316SS 1 L CSTR (continuously stirred tank reactor) rated at MAWP 5325 psig @ 510°C was used as the reaction vessel for the batch slurry tests. The conditions selected for these scoping tests were 430"C
reaction temperature and 60 minute residence time. The charge hydrogen pressure was 800 psig at room temperature to obtain an operating pressure at temperature of I S00 psig. The reaction mixture was stirred at 1000 rpm. The test conditions were selected to provide measurable hydrocracking conversion of a heavy oil. Test conditions were as follows:
Pressure: 800 psig hydrogen (initial pressure at room temperature) Temperature: 430°C
Time: 60 min Feed: 400 g Catalyst:1000 ppmw (based upon molybdenum content) Stirrer:1000 rpm The clean reactor was charged with approximately 200 g of the feed and then the catalyst suspension was weighed into the reactor. The remaining feed portion was then charged with a target content of 1000 ppmw molybdenum. After flushing the reactor gas head-space three times with nitrogen, the receiver condenser was cooled in an ice/water bath at 0°C. The water from the TDM-02-water used to suspend the micro-sheets was then removed at 120°C under a nitrogen flow of 400 mL/min with constant stirring at 1000rpm. The water was collected and weighed until complete removal.
The reactor was flushed with hydrogen three times and then the system was pressurized to 800 psig. The internal temperature was raised to 430°C
with constant stirring at 1000 rpm. An internal cooling coil was employed to maintain the operating temperature within +/- 2°C of the target temperature. At the 60-min residence time the heaters were turned off, cooling water flow was initiated, and the reactor insulation was removed to return the reactor to room temperature.
Once the system was at room temperature, the reactor gas was slowly discharged through the condensers. A gas sample was obtained in a Teflon-lined gas sampling bag (Calibrated Instruments, New York) for subsequent analysis.
Reactor liquids were collected and pressure filtered to obtain a neat filtered product oil. The reactor was washed with tetrahydrofuran. This solvent was collected, pressure filtered then removed by a rotary evaporator. The oil product remaining was added to the product liquid. Collected reactor solids were dried in a vacuum oven at 100°C. Cleaning towels were used to recover mostly oil liquids collected throughout the clean-up and were recorded as losses.
The recovered liquid mass was determined and a combined product oil (neat filtered product oil plus condensate) mixture obtained. This sample was tested for density, sulfur content and simulated distillation analyses. The results of the analysis are included in DRAWING SHEETS 4 through 7 as (TDM -02). From these results it is clear that micro-dimensional sheets are more active in the catalysis of this feedstock than both molybdenum napthenate and the nano-dimensional sheets.
REFERENCES CITED:
US. Pat. No. 4,155,832 Cox et al., 1-Iydrogenation Process for Solid Carbonaceous Materials US. Pat. No. 4,299,892 Dines et al., Amorphous and Sheet Dichalcogenides of Group IVB, VB, Molybdenum and Tungsten US. Pat. No. 4,557,821 Lopez et al, Heavy Oil Hydroprocessing US. Pat No. 4,822,590 Morrison et al,. Forms of Transition Metal Dichalcogenides US. Pat. No. 4,839,326 Halbert et al., Promoted Molybdenum and Tungsten Sulfide Catalysts, Their Preparation and Use US. Pat. No 4,853,359 Momision et al, Novel Transition Metal Dichalcogenide Catalysts US. Pat.No. 4,996,108 Divigalpitiya et al., Sheets of Transition Metal Dichalcogenides US. Pat. No. 5,279,805, Miremadi et al., Gas Storage using Transition Metal Dichalcogenides US. Pat. No. 5,094,991 Lopez et al., Slurry Catalyst for Hydroprocessing Heavy and Refractory Oils US. Pat. No. 5,578,197 Cyr et al., Hydrocracking Process Involving Colloidal Catalyst Formed ln-Situ US. Pat. No. 5,916,432 McFarlane et al., Process for Dispersing Transition Metal Catalytic Particles in Heavy Oil US. Pat. No. 5,935,419 Kahn et al., Methods for Adding Value to Heavy Oil Utilizing a Soluble Metal Catalyst US. Pat. No 6,156,693 Song et al, Method for Preparing a Highly Active Unsupported High-Surface-Area MoS~ Catalyst US. Pat. No 6,143,359 Rendina, Soluble Metal HydridelTransition Metal dichalcogenide Alloys American Chemical Society, " Microstructural Characterization of Highly HDS-Active Co~,Ss-Pillared Molybdenum Sulfides" Brenner et al., Chemical Material 1998, 10, 1244-
1 1 ) Immersing the alkali metal intercalated structure in a liquid that generates a gas upon reaction with the alkali metal to thereby with suitable agitation cause the porous structure to fracture into mesoscopic dimensioned particles 12) Separating mesoseopic particles from larger particles through sedimentation, centrifuging or other known methods.
13 ) Dispersing said mesoscopic particles in a liquid matrix, preferably neat oil.
PROCESS FOR DISPERSING EXFOLIATED PARTICLES IN IMMISCIBLE
LIQUIDS
The inventors have found that it is beneficial in many cases to transfer dispersions of catalytically active materials from suspensions in water to suspensions in oils that are substantially free of water. A process for accomplishing said transfer is described below;
1 ) Initially preparing a dispersion of exfoliated transition metal dichalcogenides in water 2) Adding the desired transfer oil to the dispersion.
3) Optionally adjusting the pH of the water to less than pH7 in order to cause the exfoliated material to from at the oil/water interface.
4) Adding a surfactant to the combined oil/water composition. Preferably a cationic surfactant is used to drive the exfoliated materials further into the oil.
5) Decanting the oil and exfoliated material dispersion 6) Separating the surfactant and remaining water form the decanted oil/exfoliated material dispersion by centrifuging or settling.
As can be readily seen by one skilled in the art the order of these and previously described process steps may be modified without departing from the scope or spirit of the invention.
EXPERIMENTS
Methods employed by the present inventors to determine particle dimensions in all of the experiments disclosed include one or more of the following, direct microscopic observation, filtration, calculation of sedimentation rates by the formula;
Sedimentation rate dx/dt = [(4nr3/3)( p'-p)g]6~rt~
_ [2r2(p'-p)g~/9r1 where ~ = viscosity of surrounding medium p = density of surrounding medium p'= density of colloidal particle material r =- radius of colloidal particle Measurment of (z) dimension was by x-ray diffraction and measurement of (x) and (y) dimensions was by x-ray diffraction and calculation using the Scherrer equation.
Experiment 1 Methods for forming nano-sheets into macro-sheets Example 1 A 10 kg sample of exfoliated transition metal dichalcogenide was produced by standard methods. Immediately after the exfoliation and washing, the material was examined by x-ray diffraction and the single molecule thick sheet structure with (x) and (y) dimensions less than 100 manometers was confirmed. A 250 ml portion of the sample containing 20 mg /ml of exfoliated material in Ph 7 water was filtered through a 1 micron filter and allowed to sit undisturbed in a sealed jar at approximately 23C for three months. After the three month period the contents of the jar were again filtered at I micron and it was noted that the majority of the exfoliated material would not pass through the filter. A sample of the material retained by the filter was examined by x-ray diffraction and the single molecule thick structure was again confirmed.
Various samples were examined where the suspension medium and/or pH conditions of the water was adjusted within a range between Ph2 to Ph 14, and the age of the samples was adjusted from 1 week to 3 years. Micro-sheets having a single molecule thickness and with length and/or breadth measurements in excess of 150 microns were produced.
Example 2 Electrical conductivity tests on exfoliated transition metal dichalcogenides contained at the interface between water and immiscible organic solvents such as methylmethacrylate monomer demonstrate that namo-sheets can be induced to organize into parallel micro-sheets rapidly by using the organic molecules as templates. The speed of the micro-sheet formation may be monitored by a measurement of the increase in conductivity.
Exfoliated transition metal dichalcogenide was prepared by standard methods.
0.3 ml of methylmethacrylate (MMA) was added to the exfoliated suspension containing 0.5 g of exfoliated transition metal dichalcogenide.
Upon addition of MMA to the exfoliated transition metal dichalcogenide suspension and shaking, it was observed that the exfoliated material moves toward the water/MMA
interface.
Electrical conductivity measurements were taken using a two-point probe with a fixed separation of 13.5 mm between the probes. It was observed that the conductivity of the exfoliated transition metal dichalcogenide/MMA mixture increased over time by a factor of 10 times the conductivity on day 2.
SampleElapsed 2 days ~ 12 days ~ 22 days 35 days Time 4 0.21-0.22 1.22-1.30 I 20 ml + 0.10-0. I 2 j 0.30-0.
3 ml 0 MM ~
A
Experiment 2 Orientation of micro-sheets to form solid structures with selectable pore sizes:
Example 1 - parallel orientation with freeze dry fixing An aged exfoliated transition metal dichalcogenide, (MoS2) was dispersed in water containing 2wt% glucose polymers, where in addition to glucose the composition includes, per 100 grams, not more than 30mg calcium, l lOmg sodium, l Omg potassium, 223mg chloride, and Smg phosphorous. The samples centrifuged to create a paste and then freeze-dried. Once dry, a portion of the solid freeze-dried sample was re-suspended in the original solvents and examined by X-ray diffraction along with its control.
The results of the X-ray showed that the freeze-dried sample had the same characteristic pattern indicating single molecule thick sheets as the control sample, thus indicating that the parallel oriented single molecule structure had been maintained in the resulting solid. A portion of the freeze-dried sample was heated under controlled atmosphere to evolve the inclusion and generate a micro-porous structure.
Example 2 - perpendicular orientation with different size sheets and heat fixing Two 250 ml samples of exfoliated MoS~ were prepared by standard techniques and dispersed in water (water suspension, 2.1% exfoliated material). One sample labeled DMC024 had been aged for 2 months in neutral pH water, the other labeled DMC006 was freshly made.
Approximately 500 ml HNO, solution (pH 1.82) was added drop-wise to each of the suspensions and stirred.
- The pH of the samples were adjusted the by adding more HN03 solution in small amounts to reach a pH of 1.97. Sowing and pH control was maintained for ~ 15 minutes and then solids were allowed settle. Both suspensions cleared rapidly.
The solids were retained separately with a vacuum filter through #2 filter paper. A large volume of paste is collected. Next the solids were rinsed with ~50 ml water The samples were dried in a tube furnace for 2 hours under flowing argon at and then at SOOC for 3 hours under hydrogen to create a solid porous structure. As can be seen from the table below, the sample made from older, larger, sheets had distinctly different surface area and pore sizes than the fresh exfoliated material.
1. Surface areas:
Sample Surface area, Pore volume, m2/g cm3/g DMC006 46.1 0.12 DMC024 23.6 (1.087 Experiment 3 Forming mesoscopic strucutures:
The materials produced in experiment 2 above were immersed in 2.5 molar n-butylithium in hexane for 72 hours in a dry environment. The resulting alkali metal intercalated porous structure was immersed in water. Copious quantities of gas and significant heat was generated. The porous structure was fractured smaller particles.
Particles were segregated by size through sedimentation and those in the mesoscopic range were dispersed in neat oil forming a dispersion.
Experiment 4 Catalysis using nano-sheets:
This slurry hydrocracking reaction involved the use of nano-dimensional sheets of MoS2 applied as a catalyst to upgrade Suncor, Athabasca bitumen. The sample in this case was 3 days old before use. Dimensions were shown to be approximately 6.2 angstroms in thickness (z dimension) by x-ray diffraction and less than I micron in any dimension by filtration and less than 100 nanometers in any dimension by x-ray diffraction.
a) Preparation of nano-dimensional MoS~ -g of MoS2 (Aldrich) with particle sizes of 2 microns or less was intercalated with SO ml 2.S M n-BuLi solution in hexane (Aldrich). After a minimum of 72 hours, the excess of n-BuLi and hexane was decanted and distilled water was added for the exfoliation of the MoS2. The paste reacted vigorously with the water and gases evolved. Exfoliation was completed by sonicating the mixture for 30 minutes.
'The paste was washed with water, stirred for 30 minutes, centrifuged for 30 minutes at 3000 rpm. The water was decanted and replenished with deionized distilled water and the exfoliated material was resuspended. This wash/centrifuge/decant/
resuspension cycle was repeated twice, until the pH was neutral.
b) Materials characteristics:
Feedstock - Suncor Athabasca bitumen This bitumen is the feed to a delayed coker after hot water extraction, dewatering and naphtha recovery. Relevant properties of this feed are as follows:
Carbon (wt%) 84.03 Hydrogen (wt%) 9.89 Nitrogen (wt%) 0.41 Sulfur (wt%) 4.91 Density @ 15.6C 1.016 Aromaticity, C 13 0.33 Simulated Distillation C, (wt%) IBP - 200C 0.75 200 - 343 C 10.11 343 - 525 C 35.94 525+ C 53.20 Nano-Dimensional Exfoliated MoSz (TDM - O1) -Sample Name TDM-O1 Suspension solvent: Water MoS2 concentration: 22 mg/ml Age: 3 days pH: 7.39 c) Autoclave test - An Autoclave Engineers Inc. 3165S 1 L CSTR (continuously stirred tank reactor) rated at MAWP 5325 psig @ 510°C was used as the reaction vessel for the batch slurry tests. The conditions selected for these scoping tests were 430°C reaction temperature and 60 minute residence time. The charge hydrogen pressure was 800 psig at room temperature to obtain an operating pressure at temperature of 1500 psig. The reaction mixture was stirred at 1000 rpm. The test conditions were selected to provide measurable hydrocracking conversion of a heavy oil. A blank thermal run was done with the same parameters except for the addition of a catalyst.. Test conditions were as follows:
Pressure:800 psig hydrogen (initial pressure at room temperature) Temperature:430C
Time: 60 min Feed: 400 g Catalyst:1000 ppmw (based upon molybdenum content) Stirrer:1000 rpm The clean reactor was charged with approximately 200 g of the feed and then the catalyst suspension was weighed into the reactor. The remaining feed portion was then charged with a target content of 1000 ppmw molybdenum. After flushing the reactor gas head-space three times with nitrogen, the receiver condenser was cooled in an ice/water bath at 0°C. The water from the TDM-water suspension was then removed at 120°C under a nitrogen flow of 400 mL/min with constant stirring at 1000rpm. The water was collected and weighed until complete removal.
The reactor was flushed with hydrogen three times and then the system was pressurised to 800 psig. The internal temperature was raised to 430°C
with constant stirring at 1000 rpm. An internal cooling coil was employed to maintain the operating temperature within +i- 2°C of the target temperature. At the 60-min residence time the heaters were turned off, cooling water flow was initiated, and the reactor insulation was removed to return the reactor to room temperature.
Once the system was at room temperature, the reactor gas was slowly discharged through the condensers. A gas sample was obtained in a Teflon-lined gas sampling bag (Calibrated Instruments, New York) for subsequent analysis.
Reactor liquids were collected and pressure filtered to obtain a neat filtered product oil. The reactor was washed with tetrahydrofuran. This solvent was collected, pressure filtered then removed by a rotary evaporator. The oil product remaining was added to the product liquid. Collected reactor solids were dried in a vacuum oven at 100°C. Cleaning towels were used to recover mostly oil liquids collected throughout the clean-up and were recorded as losses.
The recovered liquid mass was determined and a combined product oil (neat filtered product oil plus condensate) mixture obtained. This sample was tested for density, sulfur content and simulated distillation analyses. The results of the analysis are included in DRAWING SHEETS 4 through 7 as (TDM -Ol ). From these results it is clear that nano-dimensional sheets are more active in the catalysis of this feedstock than molybdenum napthenate.
Experiment 5 Catalysis using nano-sheets with promoters:
This slurry hydrocracking reaction involved the use of~ an inclusion of a soluble magnesium hydride inclusion between nano-sheets of exfoliated MoS2 as the catalyst for the hydro-conversion of Suncor, Athabasca bitumen.
a) Preparation of exfoliated MoSz followed the same procedure and aging described in experiment 2. After the third wash, the TDM was washed twice with DMF for water removal and with tetrahydrofuran (THF 99.5%, inhibited with 0.025%
BHT), and finally resuspended in THF. The suspension had a concentration of 34 mg/ml of exfoliated MoS2. The soluble magnesium hydride was prepared by known methods, starting with dioctylmagnesium as the dialkylmagnesium precursor. Lastly, the MgH2 was included between sheets of the exfoliated MoS2 to form a microstructure with a parallel sheet orientation.
b) Materials characteristics:
Suncor Athabasca bitumen: See Example 1b).
Catalyst sample TDM-metal hydride suspension:
Sample Name TDM-03 Suspension solvent:THF
Mo concentration 2.58 (w/w '%):
Mg concentration 0.54 (w/w%) Impurities (w/w%) 2.18 Age: 3 days The tetrahydrofuran suspension was removed at 80°C under a gas flow for 2 hours. Little tetrahydrofuran was collected at the condenser and it appears that this solvent was flushed out by nitrogen gas flow.
c) The Autoclave test - The procedure was as described in example 1 and 2.
Amounts used: 406.58 g of bitumen, 576 ppm Mo.
The results of the analysis are included in DRAWING SHEETS 4 through ? as (TDM
-03). From these results it is clear that the addition of an inclusion material, within parallel oriented sheets, can be useful in modifying the reaction. In this case the inclusion produced a semi-solid microstructure that was more active in the catalysis of this feedstock than molybdenum napthanate.
Experiment 6 Catalysis using macro-sheets:
Macro-sheets of exfoliated single layer MoS2 (TDM-02), employed in this slurry hydrocracking reaction involved the use of macro-sheets, comprised of sheets having length and width dimensions in a range from less than 1 micron to sheets exceeding 45 microns and depth measurements of approximately 6.2 angstroms, to upgrade SL111COr, Athabasca bitumen. The length and width measurements were determined by filtration, depth dimensions were determined by x-ray diffraction. The sample (TDM - 02) was aged 5 weeks suspended in neutral pH water before use.
c) Preparation of single layer MoS2 (TDM - 02) - 10 g of MoS2 (Aldrich) was intercalated with 50 ml 2.5 M n-BuLi solution in hexane (Aldrich). After a minimum of 72 hours, the excess of n-BuLi and hexane was decanted and distilled water was added for the exfoliation of the MoSz. The paste reacted vigorously with the water and gases evolved. Exfoliation was completed by sonicating the mixture for 30 minutes. The paste was washed with water, stirred for 30 minutes, centrifuged for 30 minutes at 3000 rpm and decanted. This wash/centrifuge/decant cycle was repeated twice, until the pH was neutral.
d) Materials characteristics:
Feedstock - Suncor Athabasca bitumen This bitumen is the feed to a delayed coker after hot water extraction, dewatering and naphtha recovery.
Macro-sheets of exfoliated MoSZ (TDM-02) -Sample Name TDM-02 Suspension solvent:Water MoS~ concentration:22 mg/ml Age: 5 weeks PH: 7.39 Autoclave test - An Autoclave Engineers Inc. 316SS 1 L CSTR (continuously stirred tank reactor) rated at MAWP 5325 psig @ 510°C was used as the reaction vessel for the batch slurry tests. The conditions selected for these scoping tests were 430"C
reaction temperature and 60 minute residence time. The charge hydrogen pressure was 800 psig at room temperature to obtain an operating pressure at temperature of I S00 psig. The reaction mixture was stirred at 1000 rpm. The test conditions were selected to provide measurable hydrocracking conversion of a heavy oil. Test conditions were as follows:
Pressure: 800 psig hydrogen (initial pressure at room temperature) Temperature: 430°C
Time: 60 min Feed: 400 g Catalyst:1000 ppmw (based upon molybdenum content) Stirrer:1000 rpm The clean reactor was charged with approximately 200 g of the feed and then the catalyst suspension was weighed into the reactor. The remaining feed portion was then charged with a target content of 1000 ppmw molybdenum. After flushing the reactor gas head-space three times with nitrogen, the receiver condenser was cooled in an ice/water bath at 0°C. The water from the TDM-02-water used to suspend the micro-sheets was then removed at 120°C under a nitrogen flow of 400 mL/min with constant stirring at 1000rpm. The water was collected and weighed until complete removal.
The reactor was flushed with hydrogen three times and then the system was pressurized to 800 psig. The internal temperature was raised to 430°C
with constant stirring at 1000 rpm. An internal cooling coil was employed to maintain the operating temperature within +/- 2°C of the target temperature. At the 60-min residence time the heaters were turned off, cooling water flow was initiated, and the reactor insulation was removed to return the reactor to room temperature.
Once the system was at room temperature, the reactor gas was slowly discharged through the condensers. A gas sample was obtained in a Teflon-lined gas sampling bag (Calibrated Instruments, New York) for subsequent analysis.
Reactor liquids were collected and pressure filtered to obtain a neat filtered product oil. The reactor was washed with tetrahydrofuran. This solvent was collected, pressure filtered then removed by a rotary evaporator. The oil product remaining was added to the product liquid. Collected reactor solids were dried in a vacuum oven at 100°C. Cleaning towels were used to recover mostly oil liquids collected throughout the clean-up and were recorded as losses.
The recovered liquid mass was determined and a combined product oil (neat filtered product oil plus condensate) mixture obtained. This sample was tested for density, sulfur content and simulated distillation analyses. The results of the analysis are included in DRAWING SHEETS 4 through 7 as (TDM -02). From these results it is clear that micro-dimensional sheets are more active in the catalysis of this feedstock than both molybdenum napthenate and the nano-dimensional sheets.
REFERENCES CITED:
US. Pat. No. 4,155,832 Cox et al., 1-Iydrogenation Process for Solid Carbonaceous Materials US. Pat. No. 4,299,892 Dines et al., Amorphous and Sheet Dichalcogenides of Group IVB, VB, Molybdenum and Tungsten US. Pat. No. 4,557,821 Lopez et al, Heavy Oil Hydroprocessing US. Pat No. 4,822,590 Morrison et al,. Forms of Transition Metal Dichalcogenides US. Pat. No. 4,839,326 Halbert et al., Promoted Molybdenum and Tungsten Sulfide Catalysts, Their Preparation and Use US. Pat. No 4,853,359 Momision et al, Novel Transition Metal Dichalcogenide Catalysts US. Pat.No. 4,996,108 Divigalpitiya et al., Sheets of Transition Metal Dichalcogenides US. Pat. No. 5,279,805, Miremadi et al., Gas Storage using Transition Metal Dichalcogenides US. Pat. No. 5,094,991 Lopez et al., Slurry Catalyst for Hydroprocessing Heavy and Refractory Oils US. Pat. No. 5,578,197 Cyr et al., Hydrocracking Process Involving Colloidal Catalyst Formed ln-Situ US. Pat. No. 5,916,432 McFarlane et al., Process for Dispersing Transition Metal Catalytic Particles in Heavy Oil US. Pat. No. 5,935,419 Kahn et al., Methods for Adding Value to Heavy Oil Utilizing a Soluble Metal Catalyst US. Pat. No 6,156,693 Song et al, Method for Preparing a Highly Active Unsupported High-Surface-Area MoS~ Catalyst US. Pat. No 6,143,359 Rendina, Soluble Metal HydridelTransition Metal dichalcogenide Alloys American Chemical Society, " Microstructural Characterization of Highly HDS-Active Co~,Ss-Pillared Molybdenum Sulfides" Brenner et al., Chemical Material 1998, 10, 1244-
Claims (9)
1. A sol comprised in part of a dispersion of catalytically active colloidal particles of transition metal dichalcogenides suspended in Brownian motion within a fluid matrix, where said catalytically active particles conform to dimensions in the range of Nano-dimensional sheets having:
1) Thickness (z) dimensions between 0.5 and 10 manometers of the selected catalytically active material, and
1) Thickness (z) dimensions between 0.5 and 10 manometers of the selected catalytically active material, and
2) Lengths (x) between > 1 manometers and up to 100 manometers, and
3) Widths (y) between >1 manometers and up to 100 manometers 2. A sol comprised in part of a dispersion of catalytically active colloidal particles of transition metal dichalcogenides suspended in Brownian motion within a fluid matrix, where said catalytically active particles conform to dimensions in the range of Macro-molecules having:
1) A thickness (z) dimension between 0.5 and 100 manometers of the selected catalytically active material, and 2) Lengths (x) of between 100 manometers and 150 microns, and 3) Widths (y) of between 100 manometers and 150 microns.
3. A sol comprised in part of a dispersion of catalytically active colloidal particles of transition metal dichalcogenides suspended in Brownian motion within a fluid matrix, where said catalytically active particles conform to dimensions in the range of Mesoscopic particles:
1) Where no particle dimension exceeds 1 micron
1) A thickness (z) dimension between 0.5 and 100 manometers of the selected catalytically active material, and 2) Lengths (x) of between 100 manometers and 150 microns, and 3) Widths (y) of between 100 manometers and 150 microns.
3. A sol comprised in part of a dispersion of catalytically active colloidal particles of transition metal dichalcogenides suspended in Brownian motion within a fluid matrix, where said catalytically active particles conform to dimensions in the range of Mesoscopic particles:
1) Where no particle dimension exceeds 1 micron
4. A process for producing catalytically active particles in suspension of the dimensions of claim 1. Said process being comprised of the following steps;
a) Segregating and selecting bulk materials of the form MX2 wherein MX2 is a layer type transition metal dichalcogenide selected from the group consisting of MoS2, TaS2, WS2, on the basis of size.
b) Intercalating multi-layer MX2 with an alkali metal in a dry environment for sufficient time to enable the alkali metal to substantially intercalate the layers of the MX2.
c) Immersing the alkali metal intercalated MX2 in a liquid that generates a gas upon reaction with the alkali metal to thereby with suitable agitation cause the layers of MX2 to separate and form a dispersion suspended in the gas generating liquid.
d) Optionally, washing and replenishing, and/or exchanging, and/or modifying the pH of the suspending liquid.
e) Optionally sorting, restacking, drying, re-intercalating, re-exfoliating, and re-suspending the MX2 particles in order to enhance the probability of producing small particles in the x, y dimensions.
f) Aging the suspension for a time and in a manner sufficient to limit the particle growth within the desired range g) Optionally, adding promoters or compositional modifiers by precipitation, adsorbtion, or inclusions of a substance or substances Y.
h) Fixing the size of the particles in suspension either by the immediate use of the dispersion as a catalyst.
i) Alternatively fixing the size of the particles in suspension by dispersing the particles in an immiscible organic liquid.
a) Segregating and selecting bulk materials of the form MX2 wherein MX2 is a layer type transition metal dichalcogenide selected from the group consisting of MoS2, TaS2, WS2, on the basis of size.
b) Intercalating multi-layer MX2 with an alkali metal in a dry environment for sufficient time to enable the alkali metal to substantially intercalate the layers of the MX2.
c) Immersing the alkali metal intercalated MX2 in a liquid that generates a gas upon reaction with the alkali metal to thereby with suitable agitation cause the layers of MX2 to separate and form a dispersion suspended in the gas generating liquid.
d) Optionally, washing and replenishing, and/or exchanging, and/or modifying the pH of the suspending liquid.
e) Optionally sorting, restacking, drying, re-intercalating, re-exfoliating, and re-suspending the MX2 particles in order to enhance the probability of producing small particles in the x, y dimensions.
f) Aging the suspension for a time and in a manner sufficient to limit the particle growth within the desired range g) Optionally, adding promoters or compositional modifiers by precipitation, adsorbtion, or inclusions of a substance or substances Y.
h) Fixing the size of the particles in suspension either by the immediate use of the dispersion as a catalyst.
i) Alternatively fixing the size of the particles in suspension by dispersing the particles in an immiscible organic liquid.
5. A process for producing catalytically active particles in suspension of the dimensions of claim 2. Said process being comprised of the following steps;
a) Intercalating multi-layer MX2 with an alkali metal in a dry environment for sufficient time to enable the alkali metal to substantially intercalate the layers of the MX2.
b) Immersing the alkali metal intercalated MX2 in a liquid that generates a gas upon reaction with the alkali metal to thereby with suitable agitation cause the layers of MX2 to separate and form a dispersion suspended in the gas generating liquid.
c) Optionally, washing and replenishing, and/or exchanging, and/or modifying the pH of the suspending liquid.
d) Aging the suspension for a time and in a manner sufficient to limit the particle growth within the desired range. Larger sheets may require longer times.
However, in all cases the growth of the sheets must be stopped before the gel point is reached.
e) Optionally, adding promoters or compositional modifiers by precipitation, adsorbtion, or inclusions of a substance or substances Y.
f) Fixing the size of the particles in suspension either by the immediate use of the dispersion as a catalyst or by dispersing the particles in immiscible organic liquids.
a) Intercalating multi-layer MX2 with an alkali metal in a dry environment for sufficient time to enable the alkali metal to substantially intercalate the layers of the MX2.
b) Immersing the alkali metal intercalated MX2 in a liquid that generates a gas upon reaction with the alkali metal to thereby with suitable agitation cause the layers of MX2 to separate and form a dispersion suspended in the gas generating liquid.
c) Optionally, washing and replenishing, and/or exchanging, and/or modifying the pH of the suspending liquid.
d) Aging the suspension for a time and in a manner sufficient to limit the particle growth within the desired range. Larger sheets may require longer times.
However, in all cases the growth of the sheets must be stopped before the gel point is reached.
e) Optionally, adding promoters or compositional modifiers by precipitation, adsorbtion, or inclusions of a substance or substances Y.
f) Fixing the size of the particles in suspension either by the immediate use of the dispersion as a catalyst or by dispersing the particles in immiscible organic liquids.
6. A process for producing catalytically active particles in suspension of the dimensions of claim 3. Said process being comprised of the following steps;
a) Segregating and selecting bulk materials of the form MX2 wherein MX2 is a layer type transition metal dichalcogenide selected from the group consisting of MoS2, TaS2, WS2, on the basis of size.
b) Intercalating multi-layer MX2 with an alkali metal in a dry environment for sufficient time to enable the alkali metal to substantially intercalate the layers of the MX2.
c) Immersing the alkali metal intercalated MX2 in a liquid that generates a gas upon reaction with the alkali metal to thereby with suitable agitation cause the layers of MX2 to separate and form a dispersion suspended in the gas generating liquid.
d) Optionally, washing and replenishing, and/or exchanging, and/or modifying the pH of the suspending liquid.
e) Optionally sorting, restacking, drying, re-intercalating, re-exfoliating, and re-suspending the MX2 particles in order to enhance the probability of producing small particles in the x, y dimensions.
f) Aging the suspension for a time and in a manner sufficient to limit the particle growth within the desired range.
g) Optionally, adding promoters or compositional modifiers by precipitation, adsorbtion, or inclusions of a substance or substances Y.
h) Separating the particles from the first dispersing liquid i) Drying the particles in a manner such that the particles form a solid porous structure.
j) Intercalating the thus formed porous structure with an alkali metal in a dry environment.
k) Immersing the alkali metal intercalated structure in a liquid that generates a gas upon reaction with the alkali metal to thereby with suitable agitation cause the porous structure to fracture into mesoscopic dimensioned particles l) Separating mesoscopic particles in suspension from larger particles.
m) Dispersing said mesoscopic particles in a liquid matrix.
a) Segregating and selecting bulk materials of the form MX2 wherein MX2 is a layer type transition metal dichalcogenide selected from the group consisting of MoS2, TaS2, WS2, on the basis of size.
b) Intercalating multi-layer MX2 with an alkali metal in a dry environment for sufficient time to enable the alkali metal to substantially intercalate the layers of the MX2.
c) Immersing the alkali metal intercalated MX2 in a liquid that generates a gas upon reaction with the alkali metal to thereby with suitable agitation cause the layers of MX2 to separate and form a dispersion suspended in the gas generating liquid.
d) Optionally, washing and replenishing, and/or exchanging, and/or modifying the pH of the suspending liquid.
e) Optionally sorting, restacking, drying, re-intercalating, re-exfoliating, and re-suspending the MX2 particles in order to enhance the probability of producing small particles in the x, y dimensions.
f) Aging the suspension for a time and in a manner sufficient to limit the particle growth within the desired range.
g) Optionally, adding promoters or compositional modifiers by precipitation, adsorbtion, or inclusions of a substance or substances Y.
h) Separating the particles from the first dispersing liquid i) Drying the particles in a manner such that the particles form a solid porous structure.
j) Intercalating the thus formed porous structure with an alkali metal in a dry environment.
k) Immersing the alkali metal intercalated structure in a liquid that generates a gas upon reaction with the alkali metal to thereby with suitable agitation cause the porous structure to fracture into mesoscopic dimensioned particles l) Separating mesoscopic particles in suspension from larger particles.
m) Dispersing said mesoscopic particles in a liquid matrix.
7. A process for transferring the dispersion of particles of claim 1 from a water matrix to an immiscible organic matrix. Said process being comprised of the following steps;
a) Initially preparing a dispersion of said particles in water b) Adding the desired transfer oil to the dispersion.
c) Optionally adjusting the pH of the water to less than pH7 in order to cause the exfoliated material to from at the oil/water interface.
d) Adding a surfactant to the combined oil/water composition.
e) Decanting the oil with the said dispersion of particles f) Separating the surfactant and remaining water form the decanted oil and particle dispersion.
a) Initially preparing a dispersion of said particles in water b) Adding the desired transfer oil to the dispersion.
c) Optionally adjusting the pH of the water to less than pH7 in order to cause the exfoliated material to from at the oil/water interface.
d) Adding a surfactant to the combined oil/water composition.
e) Decanting the oil with the said dispersion of particles f) Separating the surfactant and remaining water form the decanted oil and particle dispersion.
8. A process for transferring the dispersion of particles of claim 2 from a water matrix to an immiscible organic matrix. Said process being comprised of the following steps;
a) Initially preparing a dispersion of said particles in water b) Adding the desired transfer oil to the dispersion.
c) Optionally adjusting the pH of the water to less than pH7 in order to cause the exfoliated material to from at the oil/water interface.
d) Adding a surfactant to the combined oil/water composition.
e) Decanting the oil with the said dispersion of particles f) Separating the surfactant and remaining water form the decanted oil and particle dispersion.
a) Initially preparing a dispersion of said particles in water b) Adding the desired transfer oil to the dispersion.
c) Optionally adjusting the pH of the water to less than pH7 in order to cause the exfoliated material to from at the oil/water interface.
d) Adding a surfactant to the combined oil/water composition.
e) Decanting the oil with the said dispersion of particles f) Separating the surfactant and remaining water form the decanted oil and particle dispersion.
9. A process for transferring the dispersion of particles of claim 3 from a water matrix to an immiscible organic matrix. Said process being comprised of the following steps;
g) Initially preparing a dispersion of said particles in water h) Adding the desired transfer oil to the dispersion.
i) Optionally adjusting the pH of the water to less than pH7 in order to cause the exfoliated material to from at the oil/water interface.
j) Adding a surfactant to the combined oil/water composition.
k) Decanting the oil with the said dispersion of particles l) Separating the surfactant and remaining water form the decanted oil and particle dispersion.
g) Initially preparing a dispersion of said particles in water h) Adding the desired transfer oil to the dispersion.
i) Optionally adjusting the pH of the water to less than pH7 in order to cause the exfoliated material to from at the oil/water interface.
j) Adding a surfactant to the combined oil/water composition.
k) Decanting the oil with the said dispersion of particles l) Separating the surfactant and remaining water form the decanted oil and particle dispersion.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US22309602A | 2002-08-07 | 2002-08-07 | |
| US10/223,096 | 2002-08-07 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2431535A1 true CA2431535A1 (en) | 2004-02-07 |
Family
ID=31495292
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2431535 Abandoned CA2431535A1 (en) | 2002-08-07 | 2003-06-07 | Colloidal catalyst |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2431535A1 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103203463A (en) * | 2013-03-21 | 2013-07-17 | 上海大学 | Preparation method of molybdic sulfide nanosheet/sliver nanoparticle composite material |
| CN108163894A (en) * | 2017-12-21 | 2018-06-15 | 浙江山峪科技股份有限公司 | A kind of ultrahigh concentration stripping means of transient metal sulfide |
| CN111470536A (en) * | 2020-05-29 | 2020-07-31 | 合肥工业大学 | High-performance tantalum disulfide two-dimensional layered film and preparation method and application thereof |
-
2003
- 2003-06-07 CA CA 2431535 patent/CA2431535A1/en not_active Abandoned
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103203463A (en) * | 2013-03-21 | 2013-07-17 | 上海大学 | Preparation method of molybdic sulfide nanosheet/sliver nanoparticle composite material |
| CN108163894A (en) * | 2017-12-21 | 2018-06-15 | 浙江山峪科技股份有限公司 | A kind of ultrahigh concentration stripping means of transient metal sulfide |
| CN108163894B (en) * | 2017-12-21 | 2020-02-21 | 浙江山峪科技股份有限公司 | Ultrahigh-concentration stripping method for transition metal sulfide |
| CN111470536A (en) * | 2020-05-29 | 2020-07-31 | 合肥工业大学 | High-performance tantalum disulfide two-dimensional layered film and preparation method and application thereof |
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