CN111790376A - Sub-nanometer metal catalyst and preparation method and application thereof - Google Patents
Sub-nanometer metal catalyst and preparation method and application thereof Download PDFInfo
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Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
- B01J23/40—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals of the platinum group metals
- B01J23/42—Platinum
-
- B01J35/394—
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
- C01B3/02—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen
- C01B3/04—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by decomposition of inorganic compounds, e.g. ammonia
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/36—Hydrogen production from non-carbon containing sources, e.g. by water electrolysis
Abstract
The invention provides a sub-nano metal catalyst and a preparation method and application thereof, belonging to the technical field of sub-nano catalysis. The invention can form an epoxy group on the surface of the carrier material layer through the pulse ozone, thereby providing a stable and single growth site for the preparation of the sub-nano metal catalyst; then, the invention adopts an atomic layer deposition method to load the sub-nano metal on the carrier, and can prepare the highly dispersed and well-uniform sub-nano metal catalyst. Meanwhile, the sub-nano metal catalyst is prepared by adopting an atomic layer deposition method, calcination treatment is not needed, and accurate regulation and control of the epoxy group content and the sub-nano metal content and size can be conveniently realized by regulating and controlling operation parameters; the sub-nanometer metal catalyst prepared by the method provided by the invention has excellent activity and stability.
Description
Technical Field
The invention relates to the technical field of sub-nanometer catalysis, in particular to a sub-nanometer metal catalyst and a preparation method and application thereof.
Background
Research shows that, for the supported metal catalyst, the reduction of the size of the active component greatly affects the performance of the catalyst, because the active sites generally exist on the surface of the catalyst, and the metal component which is not in contact with the reactant in the catalyst does not participate in the reaction, so that the regulation of the distribution and structure of the atoms on the surface of the catalyst by controlling the size, morphology and crystal face of the active component is an effective means for improving the catalytic performance. When the size of the metal nano-particles is reduced, the proportion of metal atoms exposed on the surface of the catalyst is obviously increased, the atom utilization rate is greatly improved, and the change of properties such as a catalyst energy level structure, an electronic structure, a quantum size effect, an unsaturated coordination environment, metal-carrier interaction and the like can be caused; at the same time, the adsorption and desorption selectivity of active components on the catalyst to reactant molecules can be changed, thereby influencing the reaction kinetics and the catalytic reaction process, such as breakthrough
-Evans-Polanyi (BEP) relationship limitation, kinetic compensation effect limitation and the like, so that the sub-nanometer catalyst shows different activity, selectivity and stability from the traditional nanometer catalyst, and therefore the catalytic theory of the traditional nanometer catalyst is not suitable for the sub-nanometer catalyst.
Some progress has been made in the current research on sub-nanoscale catalysts, but the rational preparation of sub-nanoscale metal catalysts of controllable electronic and atomic structure remains a challenging task. The method for preparing the sub-nanometer metal catalyst in the prior art mainly comprises a mass separation/soft landing method and a ligand protection method, and has the problems of harsh preparation conditions, ligand coverage of active sites, difficulty in accurately regulating the content and size of metal active components at sub-nanometer level and the like.
Disclosure of Invention
The invention aims to provide a sub-nano metal catalyst and a preparation method and application thereof.
In order to achieve the above object, the present invention provides the following technical solutions:
the invention provides a preparation method of a sub-nano metal catalyst, which comprises the following steps:
mixing a carrier material and a diluent, coating the obtained mixture on the surface of a substrate, and forming a carrier material layer on the surface of the substrate after drying;
etching the surface of the carrier material layer based on pulse oxidation pretreatment to obtain a defect material rich in an epoxy group, and forming a defect material layer rich in the epoxy group on the surface of the substrate; the oxidant adopted by the pulse oxidation pretreatment is ozone;
based on an atomic layer deposition method, metal deposition treatment is carried out on the surface of the epoxy group-rich defective material layer through sequentially pulsing a gaseous metal precursor and a gaseous oxidant to obtain sub-nano metal existing in an atom dispersion form, and a sub-nano metal catalyst is obtained on the surface of the substrate.
Preferably, the support material comprises an oxide-based support material, a carbon support material or a carbide-based support material; the diluent comprises ethanol, methanol, acetone, n-hexane, chloroform or water; the thickness of the carrier material layer is less than or equal to 0.2 cm.
Preferably, the epoxy group content in the epoxy group-rich defective material is 0.5 to 8 at.%.
Preferably, the operation step of the pulse oxidation pretreatment comprises:
placing the substrate with the surface containing the carrier material layer in an atomic layer deposition cavity or a tubular furnace, pulsing ozone into the atomic layer deposition cavity or the tubular furnace, and after holding the atmosphere, carrying out vacuum purging to remove redundant ozone;
sequentially carrying out pulse ozone-held gas-oxidation-vacuum purging, recording as 1 etching treatment, and forming an epoxy group-rich defect material layer on the surface of the substrate after n etching treatments; and n is 1-300.
Preferably, the size of the sub-nano metal is less than or equal to 1.5 nm; the content of the sub-nano metal in the sub-nano metal catalyst is 0.1-10 wt.%.
Preferably, the atomic layer deposition method comprises the following operation steps:
placing the substrate with the surface containing the defect material layer rich in the epoxy group in an atomic layer deposition cavity, and after first gas retaining, removing redundant metal precursor by first vacuum purging to the metal precursor in a pulse gas state in the atomic layer deposition cavity; then, after second gas holding, removing redundant oxidant by second vacuum purging;
marking a metal precursor in a pulse gas state, a first gas retaining state, a first vacuum purging state, an oxidant in a pulse gas state, a second gas retaining state and a second vacuum purging state as 1-time metal deposition treatment, and obtaining a sub-nano metal catalyst on the surface of the substrate after m-time metal deposition treatment; and m is 1-30.
Preferably, the metal precursor comprises trimethyl (methylcyclopentadienyl) platinum, palladium hexafluoroacetylacetonate, ferrocene, cobaltocene, bis (2,2,6, 6-tetramethyl-3, 5-heptanedionato) copper, nickelocene or manganese diethylmetallocene.
Preferably, the oxidizing agent comprises oxygen, ozone or hydrogen peroxide.
The invention provides a sub-nanometer metal catalyst prepared by the preparation method in the technical scheme, which comprises a carrier and sub-nanometer metal, wherein the sub-nanometer metal is modified on the surface of the carrier in an atom dispersion form.
The invention provides application of the sub-nanometer metal catalyst in the technical scheme in catalyzing ammonia borane hydrolysis hydrogen production reaction or catalyzing liquid phase hydrogenation reaction.
The invention provides a preparation method of a sub-nano metal catalyst, which comprises the following steps: mixing a carrier material and a diluent, coating the obtained mixture on the surface of a substrate, and forming a carrier material layer on the surface of the substrate after drying; surface of the support material layer based on pulse oxidation pretreatmentEtching the surface to obtain a defect material rich in epoxy groups, forming a defect material layer rich in epoxy groups on the surface of the substrate, wherein the oxidant adopted in the pulse oxidation pretreatment is ozone; based on an atomic layer deposition method, metal deposition treatment is carried out on the surface of the epoxy group-rich defective material layer through sequentially pulsing a gaseous metal precursor and a gaseous oxidant to obtain sub-nano metal existing in an atom dispersion form, and a sub-nano metal catalyst is obtained on the surface of the substrate. The invention can form an epoxy group on the surface of the carrier material layer through the pulse ozone, thereby providing a stable and single growth site for the preparation of the sub-nano metal catalyst; then, the invention adopts an atomic layer deposition method to load the sub-nano metal on the carrier, and can prepare the highly dispersed and well-uniform sub-nano metal catalyst. Meanwhile, the sub-nano metal catalyst is prepared by adopting an atomic layer deposition method, calcination treatment is not needed, and accurate regulation and control of the epoxy group content and the sub-nano metal content and size can be conveniently realized by regulating and controlling operation parameters; the sub-nanometer metal catalyst prepared by the method provided by the invention has better activity and stability. The results of the examples show that the sub-nano metal catalyst provided by the invention is used for catalyzing ammonia borane hydrolysis hydrogen production reaction, and 110mL of H is produced in 2.25 minutes under the experimental conditions of the example 12After six cycles of stability tests, the activity of the sub-nano metal catalyst is about 90 percent of the initial reaction activity.
Drawings
Fig. 1 is a schematic flow diagram of the preparation of a sub-nano metal catalyst in the present invention (specifically, graphene is used as a support material, and trimethyl (methylcyclopentadienyl) platinum is used as a metal precursor);
FIG. 2 shows 5Pt/G1600-O prepared in example 13-HAADF-STEM map of 60;
FIG. 3 shows 5Pt/G1600-O prepared in example 13Synchrotron radiation X-ray absorption spectrum of-60 (reference samples are Ptfoil and PtO)2)；
FIG. 4 shows 5Pt/G1600-O prepared in example 13-60 optimal coordination structure diagram obtained by DFT calculation.
Detailed Description
The invention provides a preparation method of a sub-nano metal catalyst, which comprises the following steps:
mixing a carrier material and a diluent, coating the obtained mixture on the surface of a substrate, and forming a carrier material layer on the surface of the substrate after drying;
etching the surface of the carrier material layer based on pulse oxidation pretreatment to obtain a defect material rich in an epoxy group, and forming a defect material layer rich in the epoxy group on the surface of the substrate; the oxidant adopted by the pulse oxidation pretreatment is ozone;
based on an atomic layer deposition method, metal deposition treatment is carried out on the surface of the epoxy group-rich defective material layer through sequentially pulsing a gaseous metal precursor and a gaseous oxidant to obtain sub-nano metal existing in an atom dispersion form, and a sub-nano metal catalyst is obtained on the surface of the substrate.
The invention mixes the carrier material and the thinner, coats the obtained mixture on the surface of a substrate, and forms a carrier material layer on the surface of the substrate after drying. In the present invention, the support material preferably includes an oxide-based support material, a carbon support material, or a carbide-based support material, the oxide-based support material may specifically be titanium oxide or zinc oxide, the carbon support material may specifically be graphene or carbon nanofibers, and the carbide-based support material may specifically be tungsten carbide. The carrier material of the present invention is not particularly limited in its origin, and can be prepared by commercially available methods or well-known methods well known to those skilled in the art. In the present invention, the support material is preferably in the form of a powder, and the particle size of the support material is not particularly limited in the present invention. In the embodiment of the present invention, particularly, graphene is used as a carrier material, and the graphene is preferably prepared by a rapid thermal expansion method (refer to Structural development and analysis of thermally induced graphene nanosheets for applications in supercapacitors, carbon 2012,50,3572, 3584); the graphene prepared by the method has a complete surface and contains a small amount of epoxy groups, the epoxy group content is only 0.19 at.%, and the surface of the graphene still needs to be etched by pulse ozone to improve the epoxy group content, so that the sub-nano metal can be anchored conveniently, and the sub-nano metal content in the sub-nano metal catalyst is improved; otherwise, the sub-nano metal has poor anchoring effect, the sub-nano metal has small carrying capacity and is easy to agglomerate, so that the catalytic effect of the sub-nano metal catalyst is poor.
After the carrier material is obtained, the carrier material and the diluent are mixed, the obtained mixture is coated on the surface of a substrate, and a carrier material layer is formed on the surface of the substrate after drying. In the present invention, the diluent preferably includes ethanol, methanol, acetone, n-hexane, chloroform or water, more preferably ethanol; the concentration of the carrier material in the mixture is preferably 0.01-0.05 g/mL, and more preferably 0.01-0.02 g/mL. The substrate is not particularly limited in the present invention, and in the embodiment of the present invention, a quartz plate (having a size of 8cm × 8cm) may be specifically used. The coating is not particularly limited in the present invention, and uniform coating can be achieved by methods well known to those skilled in the art. The drying is not particularly limited, and the drying can be performed naturally at room temperature or in an oven at 30-50 ℃. In the present invention, the thickness of the layer of the support material is preferably 0.2cm or less, more preferably 0.15cm or less, and still more preferably 0.1cm or less.
After the carrier material layer is obtained, etching the surface of the carrier material layer based on pulse oxidation pretreatment to obtain a defect material rich in an epoxy group, and forming the defect material layer rich in the epoxy group on the surface of the substrate; the oxidant adopted by the pulse oxidation pretreatment is ozone. In the invention, the content of epoxy groups in the epoxy-rich defect material is preferably 0.5 to 8 at.%, more preferably 1.5 to 6 at.%, and even more preferably 2 to 4 at.%. In the invention, the oxidant adopted in the pulse oxidation pretreatment is ozone; the ozone is preferably generated by high-purity oxygen (99.999%) through an ozone generator, wherein the gas generated by the ozone generator is actually a mixed gas of ozone and the high-purity oxygen, and the mass concentration of the ozone in the mixed gas is preferably 3-30%.
In the present invention, the operation steps of the pulse oxidation pretreatment preferably include:
placing the substrate with the surface containing the carrier material layer in an atomic layer deposition cavity or a tubular furnace, pulsing ozone into the atomic layer deposition cavity or the tubular furnace, and after holding the atmosphere, carrying out vacuum purging to remove redundant ozone;
sequentially carrying out pulse ozone-held gas-oxidation-vacuum purging, recording as 1 etching treatment, and forming an epoxy group-rich defect material layer on the surface of the substrate after n etching treatments; and n is 1-300.
In the invention, the process of preparing the epoxy-rich defect material based on the pulse oxidation pretreatment can be carried out in an atomic layer deposition cavity, specifically in the atomic layer deposition cavity of the atomic layer deposition equipment, wherein the temperature of the atomic layer deposition cavity is preferably 100-350 ℃, more preferably 200-300 ℃, and further preferably 250-280 ℃; the pressure of the cavity is preferably 10-250 Pa, more preferably 30-150 Pa, and further preferably 50-110 Pa; in every minute, the volume ratio of the carrier gas flow to the atomic layer deposition cavity is 1: (5-10) introducing carrier gas, wherein the flow of the carrier gas is kept constant in the preparation process; the carrier gas is preferably nitrogen, argon or helium, and the purity is preferably more than or equal to 99.999 percent.
In the invention, the process of preparing the epoxy-rich defective material based on the pulse oxidation pretreatment can also be carried out in a tubular furnace, wherein the temperature of a cavity of the tubular furnace is preferably 100-400 ℃, more preferably 200-300 ℃, and further preferably 240-290 ℃; the pressure of the cavity is preferably 10-300 Pa, more preferably 50-200 Pa, and further preferably 80-140 Pa; in every minute, the volume ratio of the carrier gas flow to the cavity of the tube furnace is 1: (5-15) introducing carrier gas, wherein the flow of the carrier gas is kept constant in the preparation process; the carrier gas is preferably nitrogen, argon or helium, and the purity is preferably more than or equal to 99.999 percent.
In the invention, after ozone is pulsed into the atomic layer deposition cavity or the tube furnace, the ozone is chemically adsorbed on the surface of the carrier material layer, and after gas holding, redundant ozone is removed by vacuum purging, thus completing etching treatment for 1 time; and after n times of etching treatment, forming a defect material layer rich in epoxy groups on the surface of the substrate. In the present invention, the number n of etching treatments is preferably 1 to 300, more preferably 30 to 120, and further preferably 60 to 90. In the present invention, the operating parameters of the single etching process preferably include: the temperature of the ozone is 20-60 ℃, the pulse time is 0.5-15 seconds, the breath holding time is 5-60 seconds, and the vacuum purging time is 20-100 seconds; more preferably, it comprises: the temperature of the ozone is 25-45 ℃, the pulse time is 1-10 seconds, the breath holding time is 10-40 seconds, and the vacuum purging time is 20-80 seconds. In the present invention, when n.gtoreq.2, the operating parameters for each etching treatment are preferably selected within the above-mentioned ranges, and the operating parameters for each etching treatment may be the same or different, preferably the same.
The surface of the carrier material layer is etched based on pulse oxidation pretreatment, and ozone oxidizes the surface of the carrier material layer through pulse ozone in the air holding process to form an epoxy group. According to the invention, the content of the epoxy group is preferably controlled by controlling the number of etching treatment and operation parameters, and the epoxy group content is reduced when the number of etching treatment is too large or too small; specifically, taking graphene as a carrier material for example, during the etching process, oxygen-containing groups in the graphene are mutually converted, and when the number of etching times is too large, carbon atoms on the surface of the graphene are converted into CO2Or CO runs off and then leaves defects, resulting in a decrease in C attached to O atoms, resulting in a decrease in the epoxy group content, a decrease in the anchoring sites of the atomic-scale metal, resulting in a decrease in the dispersibility of the atomic-scale metal; too few etching times can also result in too little epoxy group content, too few anchoring sites of atomic metal, resulting in metal atom agglomeration and reduced number of catalytically active sites, thereby resulting in poor activity and stability of the catalyst.
After the epoxy-rich defect material layer is obtained, metal deposition treatment is carried out on the surface of the epoxy-rich defect material layer through sequentially pulsing a gaseous metal precursor and a gaseous oxidant on the basis of an atomic layer deposition method to obtain sub-nano metal existing in an atomic dispersion form, and a sub-nano metal catalyst is obtained on the surface of the substrate. In the present invention, the size of the sub-nano metal is preferably less than or equal to 1.5nm, more preferably less than or equal to 1 nm; the content of the sub-nanometer metal in the sub-nanometer metal catalyst is preferably 0.1-10 wt.%, and more preferably 1-5 wt.%.
In the present invention, the atomic layer deposition method preferably includes the steps of:
placing the substrate with the surface containing the defect material layer rich in the epoxy group in an atomic layer deposition cavity, and after first gas retaining, removing redundant metal precursor by first vacuum purging to the metal precursor in a pulse gas state in the atomic layer deposition cavity; then, after second gas holding, removing redundant oxidant by second vacuum purging;
marking a metal precursor in a pulse gas state, a first gas retaining state, a first vacuum purging state, an oxidant in a pulse gas state, a second gas retaining state and a second vacuum purging state as 1-time metal deposition treatment, and obtaining a sub-nano metal catalyst on the surface of the substrate after m-time metal deposition treatment; and m is 1-30.
In the present invention, the metal precursor preferably includes trimethyl (methylcyclopentadienyl) platinum, palladium hexafluoroacetylacetonate, ferrocene, cobaltocene, bis (2,2,6, 6-tetramethyl-3, 5-heptanedionato) copper, nickelocene or manganese diethylmetallocenes, and accordingly, the metal element in the sub-nano metal catalyst preferably includes platinum, palladium, iron, cobalt, copper, nickel or manganese. In the present invention, the oxidizing agent includes oxygen, ozone or hydrogen peroxide; in the invention, the ozone is preferably generated by passing high-purity oxygen (99.999%) through an ozone generator, wherein the gas generated by the ozone generator is actually a mixed gas of ozone and the high-purity oxygen, and the mass concentration of the ozone in the mixed gas is preferably 3-30%; the hydrogen peroxide is preferably used in the form of aqueous hydrogen peroxide (namely hydrogen peroxide), and the mass concentration of the hydrogen peroxide is preferably 10-50%.
In the invention, the process of preparing the sub-nano metal on the surface of the carrier material layer rich in the epoxy group based on the atomic layer deposition method is specifically carried out in an atomic layer deposition cavity of atomic layer deposition equipment, wherein the temperature of the cavity is preferably 100-300 ℃, more preferably 200-300 ℃, and further preferably 250-280 ℃; the pressure of the cavity is preferably 10-200 Pa, more preferably 30-150 Pa, and further preferably 50-100 Pa; in every minute, the volume ratio of the carrier gas flow to the atomic layer deposition cavity is 1: (5-10) introducing carrier gas, wherein the flow of the carrier gas is kept constant in the preparation process; the carrier gas is preferably nitrogen, argon or helium, and the purity is preferably more than or equal to 99.999 percent.
In the invention, after a gaseous metal precursor is pulsed into the atomic layer deposition cavity, the metal precursor is chemically adsorbed on the surface of a defect carrier rich in an epoxy group, and after gas is held, the redundant metal precursor is removed by purging; then, pulse gaseous oxidant is added into the atomic layer deposition cavity, the oxidant and the metal precursor are subjected to oxidation reaction, and after gas is held, redundant oxidant is removed by blowing, so that 1-time metal deposition treatment is completed; and obtaining the sub-nanometer metal catalyst on the surface of the substrate after m times of metal deposition treatment. The number m of metal deposition treatment is preferably 1-30, more preferably 1-8, and even more preferably 3-5. In the present invention, the operating parameters of the single metal deposition process preferably include:
the operating parameters when pulsing the gaseous metal precursor preferably include: the temperature of the metal oxide precursor is 30-120 ℃, the pulse time is 0.5-15 seconds, the gas hold-off time is 8-50 seconds, and the vacuum purging time is 20-60 seconds; more preferably, it comprises: the temperature of the metal oxide precursor is 50-90 ℃, the pulse time is 0.5-10 seconds, the gas hold-up time is 10-30 seconds, and the vacuum purging time is 25-40 seconds;
the operating parameters when pulsing the gaseous oxidant preferably include: the temperature of the oxidant is 30-50 ℃, the pulse time is 0.1-10 seconds, the gas hold-off time is 8-50 seconds, and the vacuum purging time is 20-60 seconds; more preferably, it comprises: the temperature of the oxidant is 30-40 ℃, the pulse time is 1-6 seconds, the breath holding time is 10-20 seconds, and the vacuum purging time is 20-40 seconds.
In the present invention, when m.gtoreq.2, the operating parameters for each metal deposition treatment are preferably selected within the above-mentioned ranges, and the operating parameters for each metal deposition treatment may be the same or different, preferably the same.
Based on an atomic layer deposition method, in a first gas holding process, a metal precursor is bonded with an epoxy group on the surface of a defective material rich in the epoxy group through a pulse gaseous metal precursor, then, in a second gas holding process, the metal precursor (wherein metal elements are marked as active metal elements) and the oxidant are subjected to an oxidation reaction through a pulse gaseous oxidant to obtain a sub-nano metal existing in an atomic dispersion form, wherein the sub-nano metal actually exists in a metal oxide form, namely the active metal elements are in coordination bonding with oxygen, and meanwhile, according to the selection of the type of a carrier, the active metal elements can also be in coordination bonding with related atoms on the carrier; specifically, taking graphene as an example of the carrier material, after a metal precursor and an oxidant undergo an oxidation reaction, a sub-nano metal in an atom dispersion form is formed on the surface of the graphene, and the coordination between an active metal atom and an oxygen atom (and a carbon atom) can be represented as CxMyOzM represents an active metal element, and the values of x, y and z are influenced by the type of the active metal element, specifically, x, y and z can be respectively 0-6, 1-4 and 1-4. The content and the existing form of the sub-nanometer metal are preferably controlled by controlling the number of times of metal deposition treatment and operation parameters, and particularly, under the condition of the operation parameters, when m is 1, the deposited metal exists in a monoatomic form, and when m is 2-5, the deposited metal exists in a diatomic form, and m is 2-5>5, the deposited metal is present predominantly in the form of sub-nanoclusters, while metals present in the monoatomic and/or diatomic form may also be present. In the present invention, too many metal deposition treatments result in a decrease in the activity of the sub-nano metal catalyst.
After the metal deposition treatment is finished, the substrate is preferably removed to obtain the sub-nano metal catalyst; the removing mode of the substrate is not particularly limited in the invention, and the method is known by the person skilled in the art; in the embodiment of the present invention, specifically, the sub-nano metal catalyst on the substrate may be scraped off.
Fig. 1 is a schematic flow diagram of a process for preparing a sub-nano metal catalyst in the present invention, and specifically, graphene is used as a carrier material, and trimethyl (methylcyclopentadienyl) platinum is used as a metal precursor, as shown in fig. 1, firstly, an ozone pulse is performed on graphene to obtain a defect material rich in an epoxy group, and then, based on an atomic layer deposition method, a metal deposition treatment is performed on a surface of the defect material layer rich in the epoxy group by sequentially pulsing a gaseous metal precursor and a gaseous oxidant, and under the above operating parameter conditions of the present invention, the deposited metal can exist in a monoatomic form, a diatomic form, or a sub-nanocluster form by controlling the number of metal deposition treatments.
The invention provides the sub-nano metal catalyst prepared by the preparation method in the technical scheme, which comprises a carrier and sub-nano metal, wherein the sub-nano metal is modified on the surface of the carrier in an atom dispersion form, and specifically, the sub-nano metal is modified on the surface of the carrier in at least one dispersion form of single atom, double atoms and sub-nano clusters. In the present invention, the size of the sub-nano metal in the sub-nano metal catalyst is preferably less than or equal to 1.5nm, more preferably less than or equal to 1 nm; the content of the sub-nanometer metal in the sub-nanometer metal catalyst is preferably 0.1-10 wt.%, and more preferably 1-5 wt.%.
The invention provides application of the sub-nanometer metal catalyst in the technical scheme in catalyzing ammonia borane hydrolysis hydrogen production reaction or catalyzing liquid phase hydrogenation reaction. The specific operation mode of the sub-nanometer metal catalyst for catalyzing ammonia borane hydrolysis hydrogen production reaction or catalyzing liquid phase hydrogenation reaction is not particularly limited, and the mode known by the technical personnel in the field can be adopted.
In the embodiment of the invention, the sub-nano metal catalyst is utilized to catalyze the ammonia borane hydrolysis hydrogen production reaction, specifically, the sub-nano metal catalyst, water and ammonia borane are mixed and then react, and timing is started; the hydrogen gas produced during the reaction can be measured by a typical water-filled burette until no gas is produced. In the present invention, the dosage ratio of the sub-nano metal catalyst, water and ammonia borane is preferably 13 mg: 10mL of: 1.5mmol, the water is preferably deionized water; the temperature of the reaction is preferably 25 ℃, the reaction is preferably carried out under stirring conditions, and the stirring rate is preferably 700 rpm. The sub-nano metal catalyst is preferably mixed with water, ammonia borane is added under the stirring condition for reaction, timing is started, and the catalytic performance of the sub-nano metal catalyst is represented by the hydrogen production.
In the present invention, the liquid phase hydrogenation reaction is preferably an aldehyde hydrogenation reaction to prepare alcohol, and in the embodiment of the present invention, specifically, the reaction for preparing cinnamyl alcohol by hydrogenation of cinnamyl aldehyde is exemplified by a sub-nano metal catalyst, which includes the following steps: placing the sub-nanometer metal catalyst, the cinnamaldehyde and the absolute ethyl alcohol into a high-pressure reaction kettle, sealing the high-pressure reaction kettle, replacing and cleaning the high-pressure reaction kettle with hydrogen for three times, and keeping the hydrogen atmosphere for reaction. In the present invention, the dosage ratio of the sub-nano metal catalyst, cinnamaldehyde and absolute ethyl alcohol is preferably 30 mg: 150 μ L of: 45mL, the temperature of the reaction is preferably 60 ℃, the time is preferably 6h, and the pressure (provided by hydrogen) is preferably 2 MPa; the reaction is preferably carried out under stirring, preferably at a rate of 700 rpm. In the invention, after the reaction is finished, centrifugal separation is preferably carried out to obtain a solid material (namely the used catalyst) and a liquid material, a product in the liquid material is directly analyzed by using a gas chromatography-mass spectrometer, and the catalytic performance of the sub-nano metal catalyst is represented by the conversion rate of a reactant and the selectivity of the product.
The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
(1) Preparing a graphene carrier material by adopting a rapid thermal expansion method (reference: Structural and thermal reduced graphene nanosheets for application in carbon 2012,50,3572-3584), which is marked as G1600, wherein the epoxy group content in the G1600 is 0.19 at.%; mixing the G1600 with ethanol, uniformly dispersing to obtain a suspension, coating the suspension on the surface of a quartz plate (with the size of 8cm multiplied by 8cm) with the concentration of the G1600 being 0.01G/mL, and naturally drying at room temperature (25 ℃) to form a G1600 layer (with the thickness of less than or equal to 0.15cm) on the surface of the quartz plate;
(2) placing the quartz plate containing G1600 layer in an atomic layer deposition chamber (the volume of the atomic layer deposition chamber is about 500 cm)3) The carrier gas is high-purity N2(99.999%), ozone (O) is carried out on the surface of the G1600 layer by utilizing the atomic layer deposition technology3) Etching, wherein the set etching parameters are as follows: the temperature of the cavity is 270 ℃, the pressure of the cavity is 50Pa, and the carrier gas (N) is used in the preparation process2) The flow rate is 50 mL/min; wherein, O3Is generated by an ozone generator, and the temperature is 30 ℃; specifically, ozone pulse is fed into an atomic layer deposition cavity, the pulse time is 2 seconds, the gas holding time is 30 seconds, and the vacuum purging time is 60 seconds, so that 1 etching treatment is completed; the etching treatment was repeated 60 times in total to obtain an epoxy-rich defective material (designated as G1600-O)360, epoxy group content 2.4 at.%, wherein "60" represents the number of etching treatments), i.e. the formation of G1600-O on the surface of the quartz plate3-60 layers;
(3) will contain G1600-O3-60 quartz plates are placed in an atomic layer deposition chamber (the volume of the atomic layer deposition chamber is about 500 cm)3) The carrier gas is high-purity N2(99.999%) in G1600-O by atomic layer deposition3-60 layers of surface deposited Pt metal, the deposition parameters set to: the temperature of the cavity is 270 ℃, the pressure of the cavity is 50Pa, and the carrier gas (N) is used in the preparation process2) The flow rate is 50 mL/min; wherein the temperature of a metal precursor trimethyl (methyl cyclopentadienyl) platinum is 65 ℃, and the temperature of an oxidant ozone is 30 ℃; specifically, trimethyl (methylcyclopentadienyl) platinum pulse is firstly fed into an atomic layer deposition cavity, the pulse time is 0.5 second, the breath holding time is 10 seconds, the vacuum purging time is 20 seconds, then ozone pulse is fed into the atomic layer deposition cavity, the pulse time is 1 second, the breath holding time is 10 seconds, and the vacuum purging time is 20 seconds, so farCompleting 1 deposition treatment; the deposition treatment is repeated in this way, and the deposition treatment is carried out for 5 times in total to obtain the sub-nano Pt/graphene catalyst (marked as 5 Pt/G1600-O) with dispersed platinum diatoms360, platinum content 4.96 wt.%, wherein "5" represents the number of deposition treatments), i.e. obtaining 5Pt/G1600-O on the quartz wafer surface3-60 catalyst (mixing the 5 Pt/G1600-O)360 catalyst is scraped from the surface of the quartz plate for subsequent characterization and performance testing).
5Pt/G1600-O prepared by HAADF-STEM pair3Characterization was performed at-60, and the results are shown in FIG. 2. FIG. 2 shows 5Pt/G1600-O3HAADF-STEM diagram of-60, it can be seen from FIG. 2 that Pt diatoms are uniformly dispersed on the epoxy group-rich defect carrier, and the small gray circles in FIG. 2 indicate Pt diatoms.
FIG. 3 shows 5Pt/G1600-O prepared in example 13-60 synchrotron radiation X-ray absorption spectrum with reference samples Ptfoil and PtO2Wherein A is Pt foil, PtO2And 5Pt/G1600-O3-60 Pt L3The edge XANES spectrogram, B is the corresponding Fourier transform spectrogram. As can be seen from FIG. 3, the 5Pt/G1600-O provided by the present invention3In-60, Pt is mainly in the form of Pt-O/C bond, and the p-type Pt is 5Pt/G1600-O3Fitting a Fourier transform spectrum of-60 to obtain Pt in a diatomic disperse form.
FIG. 4 shows 5Pt/G1600-O prepared in example 13The structure diagram of the optimal coordination structure obtained by DFT calculation of-60, as can be seen from FIG. 4, the 5Pt/G1600-O provided by the present invention3The optimal coordination structure of Pt diatomic in-60 is C5Pt2O。
5Pt/G1600-O prepared as in example 13-60 is a catalyst, and ammonia borane hydrolysis hydrogen production performance test is carried out in a three-neck flask, which comprises the following steps:
adding 13mg of catalyst into a three-neck flask containing 10mL of deionized water, adding 1.5mmol of ammonia borane into the three-neck flask at the stirring speed of 700rpm, carrying out reaction at the temperature of 25 ℃, and starting timing; the amount of hydrogen evolved during the reaction was measured by a typical water-filled burette until no gas was produced.
The test result shows that 5Pt/G1600-O is used360 catalytic hydrolysis of ammonia borane to produce hydrogen by using catalyst, and 110mL of H is produced in 2.25 minutes2(ii) a About 90% of the initial reactivity was retained after six cycles of stability testing according to the above conditions.
Example 2
A sub-nano Pt/graphene catalyst was prepared according to the method of example 1, differing from example 1 only in that G1600-O3The deposition treatment times of Pt metal on the surface of-60 is 1 time, and the sub-nano Pt/graphene catalyst with dispersed platinum monoatomic atoms (marked as 1 Pt/G1600-O) is obtained3-60, platinum content 1.06 wt.%, wherein "1" represents the number of depositions).
The performance test method in example 1 was followed using 1Pt/G1600-O360 catalytic ammonia borane hydrolysis hydrogen production reaction, and the test result shows that 110mL of H is produced in 21 minutes2(ii) a About 80% of the initial reactivity was retained after six cycles of stability testing according to the method of example 1.
Example 3
The sub-nanometer Pt/graphene catalyst prepared by the method in reference to the example 1 is different from the catalyst prepared in the example 1 only in that the ozone etching treatment frequency of the graphene carrier material is 30 times, and the defect material (marked as G1600-O) rich in epoxy groups is obtained3-30, epoxy group content 1.83 at.%, wherein "30" represents the number of etching treatments); then at said G1600-O3Depositing Pt metal on the basis of-30 according to the method in the embodiment 1 to finally obtain the sub-nanometer Pt/graphene catalyst (marked as 5 Pt/G1600-O)330, platinum content 4.55 wt.%, wherein "5" represents the number of deposition treatments).
The performance test method in example 1 was followed using 5Pt/G1600-O330-catalytic ammonia borane hydrolysis hydrogen production reaction, and the test result shows that 110mL of H is produced in 3.1 min2(ii) a About 70% of the initial reactivity was retained after six cycles of stability testing according to the method of example 1.
Example 4
Preparation of sub-nanometer Ni/graphene catalyst according to the method of example 1, and exampleExample 1 differs only in that in G1600-O3-60 layers of surface deposition Ni metal, specifically, setting the deposition parameters of Ni as follows: chamber temperature 270 deg.C, chamber pressure 50Pa, carrier gas (N) during deposition2) The flow rate is 50 mL/min; wherein the temperature of the metal precursor nickelocene is 70 ℃, and the temperature of the oxidant ozone is 30 ℃; pulse of nickelocene vapor is firstly fed into an atomic layer deposition cavity, the pulse time is 6 seconds, the gas holding time is 12 seconds, the vacuum purging time is 25 seconds, then the ozone pulse is fed into the atomic layer deposition cavity, the pulse time is 1 second, the gas holding time is 12 seconds, the vacuum purging time is 25 seconds, and thus 1 deposition treatment is completed; the deposition treatment is repeated in this way, and the deposition treatment is carried out for 5 times in total to obtain the sub-nanometer Ni/graphene catalyst (marked as 5 Ni/G1600-O) with the nickel atomic-level dispersion3-60, nickel content 5 wt.%, wherein "5" represents the number of deposition treatments).
The performance test method in example 1 was followed using 5Ni/G1600-O360 catalytic ammonia borane hydrolysis hydrogen production reaction, and the test result shows that 110mL of H is produced in 41 minutes2(ii) a About 85% of the initial reactivity was retained after six cycles of stability testing according to the method of example 1.
Comparative example
Referring to the method of example 1, a sub-nano metal catalyst is prepared, which is different from example 1 only in that Pt metal is directly deposited on the surface of G1600 without performing ozone etching treatment on G1600, so as to obtain an atomic-scale Pt/graphene sub-nano metal catalyst (denoted as 5Pt/G1600, Pt content is 1.12 wt.%, where "5" represents the number of deposition treatments).
The performance test method in example 1 was followed, and the results of the hydrogen production reaction by ammonia borane hydrolysis catalyzed by 5Pt/G1600 show that 110mL of H is produced in 65 minutes2The ammonia borane hydrolysis reaction rate is very slow; six cycles of stability testing according to the method of example 1 showed a significant reduction in activity, only 25% of the initial reactivity, indicating that the presence and amount of epoxy groups has a significant effect on anchoring atomic-scale Pt and catalyzing ammonia borane hydrolysis.
Example 5
5Pt/G1600-O prepared as in example 13-60 is a catalyst, and the catalytic cinnamaldehyde hydrogenation performance and stability are tested in a high-pressure reaction kettle, and the specific test results are as follows:
placing 30mg of catalyst, 150 mu L of cinnamyl aldehyde and 45mL of absolute ethyl alcohol into a high-pressure reaction kettle, sealing the high-pressure reaction kettle, replacing and cleaning the high-pressure reaction kettle with hydrogen for three times, keeping 2MPa of hydrogen atmosphere, heating the high-pressure reaction kettle to 60 ℃, keeping the stirring speed at 700rpm, and reacting for 6 hours; after the reaction is finished, centrifugal separation is carried out to obtain a solid material (namely the used catalyst) and a liquid material, and a product in the liquid material is directly analyzed by utilizing a gas chromatography-mass spectrometer.
The test result shows that 5Pt/G1600-O is utilized3-60 catalyzed cinnamaldehyde hydrogenation with cinnamaldehyde conversion of 79.2% and cinnamyl alcohol selectivity of 83.6%. The catalyst used was subjected to a cycle stability test according to the above conditions, and after 5 cycles of the cycle stability test, the conversion of cinnamaldehyde was 77.9%, and the selectivity of the product cinnamyl alcohol was 82.1%. The sub-nanometer metal catalyst prepared by the method provided by the invention has better activity and stability.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.
Claims (10)
1. A preparation method of a sub-nanometer metal catalyst is characterized by comprising the following steps:
mixing a carrier material and a diluent, coating the obtained mixture on the surface of a substrate, and forming a carrier material layer on the surface of the substrate after drying;
etching the surface of the carrier material layer based on pulse oxidation pretreatment to obtain a defect material rich in an epoxy group, and forming a defect material layer rich in the epoxy group on the surface of the substrate; the oxidant adopted by the pulse oxidation pretreatment is ozone;
based on an atomic layer deposition method, metal deposition treatment is carried out on the surface of the epoxy group-rich defective material layer through sequentially pulsing a gaseous metal precursor and a gaseous oxidant to obtain sub-nano metal existing in an atom dispersion form, and a sub-nano metal catalyst is obtained on the surface of the substrate.
2. The production method according to claim 1, wherein the support material includes an oxide-based support material, a carbon support material, or a carbide-based support material; the diluent comprises ethanol, methanol, acetone, n-hexane, chloroform or water; the thickness of the carrier material layer is less than or equal to 0.2 cm.
3. The method according to claim 1, wherein the epoxy group-rich defective material has an epoxy group content of 0.5 to 8 at.%.
4. The method according to any one of claims 1 to 3, wherein the step of operating the pulse oxidation pretreatment comprises:
placing the substrate with the surface containing the carrier material layer in an atomic layer deposition cavity or a tubular furnace, pulsing ozone into the atomic layer deposition cavity or the tubular furnace, and after holding the atmosphere, carrying out vacuum purging to remove redundant ozone;
sequentially carrying out pulse ozone-held gas-oxidation-vacuum purging, recording as 1 etching treatment, and forming an epoxy group-rich defect material layer on the surface of the substrate after n etching treatments; and n is 1-300.
5. The method of claim 1, wherein the sub-nanometal has a size of 1.5nm or less; the content of the sub-nano metal in the sub-nano metal catalyst is 0.1-10 wt.%.
6. The method according to any one of claims 1 to 3 and 5, wherein the atomic layer deposition method comprises:
placing the substrate with the surface containing the defect material layer rich in the epoxy group in an atomic layer deposition cavity, and after first gas retaining, removing redundant metal precursor by first vacuum purging to the metal precursor in a pulse gas state in the atomic layer deposition cavity; then, after second gas holding, removing redundant oxidant by second vacuum purging;
marking a metal precursor in a pulse gas state, a first gas retaining state, a first vacuum purging state, an oxidant in a pulse gas state, a second gas retaining state and a second vacuum purging state as 1-time metal deposition treatment, and obtaining a sub-nano metal catalyst on the surface of the substrate after m-time metal deposition treatment; and m is 1-30.
7. The method of claim 1, wherein the metal precursor comprises trimethyl (methylcyclopentadienyl) platinum, palladium hexafluoroacetylacetonate, ferrocene, cobaltocene, bis (2,2,6, 6-tetramethyl-3, 5-heptanedionato) copper, nickelocene, or manganese diethyldicyclopentadienate.
8. The method of claim 1 or 7, wherein the oxidizing agent comprises oxygen, ozone, or hydrogen peroxide.
9. The sub-nano metal catalyst prepared by the preparation method of any one of claims 1 to 8, which is characterized by comprising a carrier and sub-nano metal, wherein the sub-nano metal is modified on the surface of the carrier in an atom dispersion form.
10. The use of the sub-nano metal catalyst of claim 9 in catalyzing ammonia borane hydrolysis hydrogen production reaction or catalyzing liquid phase hydrogenation reaction.
Priority Applications (1)
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113275033A (en) * | 2021-04-21 | 2021-08-20 | 山东省科学院能源研究所 | Hierarchical pore molecular sieve supported metal catalyst and regulation method and application thereof |
| CN115090286A (en) * | 2022-05-16 | 2022-09-23 | 天津大学 | Cu/MXene monatomic catalyst and preparation method and application thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111013575A (en) * | 2019-12-19 | 2020-04-17 | 重庆三峡学院 | Graphene-platinum composite nanomaterial, preparation method and application thereof in degradation of environmental pollutants |
| CN111036237A (en) * | 2019-12-26 | 2020-04-21 | 中国科学院山西煤炭化学研究所 | Hydrogenation catalyst, preparation method and application thereof |
| US20200127300A1 (en) * | 2017-06-13 | 2020-04-23 | The Board Of Trustees Of The Leland Stanford Junior University | Electrochemical catalysts with enhanced catalytic activity |
-
2020
- 2020-07-28 CN CN202010735927.5A patent/CN111790376A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20200127300A1 (en) * | 2017-06-13 | 2020-04-23 | The Board Of Trustees Of The Leland Stanford Junior University | Electrochemical catalysts with enhanced catalytic activity |
| CN111013575A (en) * | 2019-12-19 | 2020-04-17 | 重庆三峡学院 | Graphene-platinum composite nanomaterial, preparation method and application thereof in degradation of environmental pollutants |
| CN111036237A (en) * | 2019-12-26 | 2020-04-21 | 中国科学院山西煤炭化学研究所 | Hydrogenation catalyst, preparation method and application thereof |
Non-Patent Citations (2)
| Title |
|---|
| BONGKI LEE ET AL.，: "Conformal Al2O3 dielectric layer deposited by atomic layer deposition for graphene-based nanoelectronics", 《APPLIED PHYSICS LETTERS》 * |
| SHUHUI SUN ET AL.，: "Single-atom Catalysis Using Pt/Graphene Achieved through Atomic Layer Deposition", 《SCIENTIFIC REPORTS》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113275033A (en) * | 2021-04-21 | 2021-08-20 | 山东省科学院能源研究所 | Hierarchical pore molecular sieve supported metal catalyst and regulation method and application thereof |
| CN115090286A (en) * | 2022-05-16 | 2022-09-23 | 天津大学 | Cu/MXene monatomic catalyst and preparation method and application thereof |
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