CN112973759B - Preparation method of metal monatomic catalyst, metal monatomic catalyst and application - Google Patents
Preparation method of metal monatomic catalyst, metal monatomic catalyst and application Download PDFInfo
- Publication number
- CN112973759B CN112973759B CN202110258913.3A CN202110258913A CN112973759B CN 112973759 B CN112973759 B CN 112973759B CN 202110258913 A CN202110258913 A CN 202110258913A CN 112973759 B CN112973759 B CN 112973759B
- Authority
- CN
- China
- Prior art keywords
- template
- metal
- solvent
- oxide
- hydroxide
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
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
- B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
- B01J27/24—Nitrogen compounds
-
- 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
- B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
- B01J27/02—Sulfur, selenium or tellurium; Compounds thereof
- B01J27/04—Sulfides
- B01J27/043—Sulfides with iron group metals or platinum group metals
-
- 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
- B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
- B01J27/14—Phosphorus; Compounds thereof
-
- 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
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/0009—Use of binding agents; Moulding; Pressing; Powdering; Granulating; Addition of materials ameliorating the mechanical properties of the product catalyst
- B01J37/0018—Addition of a binding agent or of material, later completely removed among others as result of heat treatment, leaching or washing,(e.g. forming of pores; protective layer, desintegrating by heat)
-
- 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
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/02—Impregnation, coating or precipitation
- B01J37/03—Precipitation; Co-precipitation
- B01J37/031—Precipitation
-
- 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
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/32—Freeze drying, i.e. lyophilisation
-
- 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
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/34—Irradiation by, or application of, electric, magnetic or wave energy, e.g. ultrasonic waves ; Ionic sputtering; Flame or plasma spraying; Particle radiation
- B01J37/341—Irradiation by, or application of, electric, magnetic or wave energy, e.g. ultrasonic waves ; Ionic sputtering; Flame or plasma spraying; Particle radiation making use of electric or magnetic fields, wave energy or particle radiation
- B01J37/343—Irradiation by, or application of, electric, magnetic or wave energy, e.g. ultrasonic waves ; Ionic sputtering; Flame or plasma spraying; Particle radiation making use of electric or magnetic fields, wave energy or particle radiation of ultrasonic wave energy
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C209/00—Preparation of compounds containing amino groups bound to a carbon skeleton
- C07C209/30—Preparation of compounds containing amino groups bound to a carbon skeleton by reduction of nitrogen-to-oxygen or nitrogen-to-nitrogen bonds
- C07C209/32—Preparation of compounds containing amino groups bound to a carbon skeleton by reduction of nitrogen-to-oxygen or nitrogen-to-nitrogen bonds by reduction of nitro groups
- C07C209/325—Preparation of compounds containing amino groups bound to a carbon skeleton by reduction of nitrogen-to-oxygen or nitrogen-to-nitrogen bonds by reduction of nitro groups reduction by other means than indicated in C07C209/34 or C07C209/36
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Health & Medical Sciences (AREA)
- Plasma & Fusion (AREA)
- Toxicology (AREA)
- Catalysts (AREA)
Abstract
The invention provides a preparation method of a metal monatomic catalyst, the metal monatomic catalyst and application, and relates to the technical field of catalysts. Grafting a coupling agent onto a hydroxylated template to form a first template with functionalized surface, monodispersely anchoring a metal precursor on the surface of the first template through the interaction between a functional group carried by the coupling agent and a metal atom to form a second template with a metal precursor loaded on the surface, physically coating and isolating the metal precursor on the surface of the second template by using a carbon source, and removing the template to obtain a metal monatomic catalyst; the preparation method is based on a strategy of combining chemical confinement (dispersion anchoring) and physical confinement (coating isolation) effects, realizes uniform spatial isolation and atomic-level dispersion of a metal precursor, effectively inhibits migration and agglomeration of metal in a calcination (pyrolysis) process, and achieves the purpose of accurate and controllable preparation of the metal monatomic catalyst.
Description
Technical Field
The invention relates to the technical field of catalysts, in particular to a preparation method of a metal monatomic catalyst, the metal monatomic catalyst and application.
Background
The monatomic catalyst refers to a catalyst having excellent catalytic performance in which a metal is uniformly dispersed in a monatomic form on a carrier. Compared with the traditional carrier catalyst, the monatomic catalyst has the advantages of high activity, good selectivity and the like, and because the metal active component is reduced to the atomic scale, the highest atomic utilization rate can be realized in the reaction. Therefore, the monatomic catalyst has wide application prospect in the fields of oxidation reaction, hydrogenation reaction, water gas shift, photocatalytic hydrogen production, electrochemical catalysis and the like.
Because the specific surface energy of the monoatomic is large, and the monoatomic is easy to migrate and agglomerate, the monoatomic catalyst with higher dispersity is difficult to prepare. Meanwhile, the prepared monatomic catalyst has poor thermal stability due to high surface energy and thermodynamic instability of the highly dispersed monatomic. In addition, the existing preparation method of the monatomic catalyst is complicated and has poor universality, and some adopted organic precursors have potential toxicity and high price, have high preparation cost and are not friendly to environment and organisms. Therefore, it is of great significance to find a cheap, efficient and highly universal preparation method for preparing the metal monatomic catalyst with higher dispersity and high thermal stability.
In view of the above, the present invention is particularly proposed to solve at least one of the above technical problems.
Disclosure of Invention
The first purpose of the invention is to provide a preparation method of a metal monatomic catalyst, which is used for relieving the technical problems of poor universality, high preparation cost, and poor dispersion degree and high thermal stability of the obtained metal monatomic catalyst in the existing preparation method;
a second object of the present invention is to provide a metal monoatomic catalyst.
The third purpose of the invention is to provide the application of the metal monoatomic catalyst.
In order to achieve the purpose, the technical scheme of the invention is as follows:
the invention provides a preparation method of a metal monatomic catalyst, which comprises the following steps:
(a) Providing a hydroxylated template;
mixing a hydroxylated template, a coupling agent and a solvent A, reacting, and separating to obtain a surface functionalized first template;
(b) Mixing and separating the first template, the metal precursor and the solvent B to obtain a second template with the surface loaded with the metal precursor;
(c) Mixing the second template with a carbon source, calcining under a protective atmosphere, and removing the template from the obtained calcined material to obtain the metal monatomic catalyst; wherein the penetration degree of the carbon source is 30-160/0.1mm.
Further, on the basis of the above technical solution of the present invention, in the step (a), the coupling agent includes any one of or a combination of at least two of an amino group-containing silane coupling agent, a mercapto group-containing silane coupling agent, or a phosphoric acid group-containing silane coupling agent, and preferably includes an amino group-containing silane coupling agent;
preferably, the silane coupling agent containing amino groups comprises any one or a combination of at least two of 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N- (beta-aminoethyl) -gamma-aminopropyltriethoxysilane, 3-aminopropyldimethylmethoxysilane, ethylenediamine-methyl-triethoxysilane or 3-2- (aminoethyl) aminopropyltrimethoxysilane;
preferably, the mercapto group-containing silane coupling agent includes any one of 3-mercaptopropyl (dimethoxy) silane, (3-mercaptopropyl) triethoxysilane, (3-mercaptopropyl) trimethoxysilane, or a combination of at least two thereof;
preferably, the silane coupling agent containing phosphoric acid groups includes tris (trimethylsilyl) phosphate;
preferably, in the step (a), the solvent a includes any one or a combination of at least two of methanol, ethanol, propanol, butanol, pentanol, hexanol, acetone, toluene, N-dimethylformamide, N-hexane, cyclohexane or water;
preferably, in step (a), the mass ratio of the hydroxylated template to the coupling agent to the solvent A is (0.1-1): (0.1-1): (1-10);
preferably, in step (a), the reaction temperature is 0-120 ℃ and the reaction time is 4-24h.
Further, on the basis of the above technical solution of the present invention, in the step (a), the preparation method of the hydroxylated template comprises the following steps:
mixing the template, an alkaline reagent and a solvent C, and separating to obtain a hydroxylated template;
preferably, the template comprises a metal oxide and/or a metal hydroxide;
preferably, the metal oxide comprises any one of iron oxide, aluminum oxide, magnesium oxide, calcium oxide, titanium oxide, manganese oxide, cobalt oxide, nickel oxide, copper oxide or zinc oxide or a combination of at least two of the above;
preferably, the metal hydroxide comprises any one of iron hydroxide, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, titanium hydroxide, manganese hydroxide, cobalt hydroxide, nickel hydroxide, copper hydroxide or zinc hydroxide or a combination of at least two of the foregoing;
preferably, the alkaline reagent comprises any one or a combination of at least two of sodium hydroxide, potassium carbonate, sodium carbonate, potassium amide, sodium hydride or potassium hydride;
preferably, the solvent C includes any one or a combination of at least two of methanol, ethanol, propanol, butanol, pentanol, hexanol, acetone, toluene, N-dimethylformamide, N-hexane, cyclohexane or water;
preferably, the mass ratio of the template, the alkaline agent and the solvent C is (0.1-1): (0.1-10): (10-100).
Further, on the basis of the above technical solution of the present invention, in the step (b), the metal precursor includes any one or a combination of at least two of manganese salt, iron salt, cobalt salt, nickel salt, copper salt, zinc salt, or chromium salt;
preferably, in the step (B), the solvent B includes any one or a combination of at least two of methanol, ethanol, propanol, butanol, pentanol, hexanol, acetone, toluene, N-dimethylformamide, N-hexane, cyclohexane or water;
preferably, in the step (B), the mass ratio of the first template, the metal precursor and the solvent B is (0.1-1): (0.1-1): (10-50);
preferably, in step (b), the mixing temperature is 0-80 ℃ and the mixing time is 4-24h.
Further, in the above technical solution of the present invention, in the step (c), the carbon source includes any one or a combination of at least two of asphalt, vacuum residue, FCC slurry oil or formaldehyde resin, preferably asphalt;
preferably, the asphalt comprises petroleum asphalt and/or coal asphalt, and further preferably comprises petroleum asphalt.
Further, on the basis of the above technical solution of the present invention, in the step (c), the mass ratio of the second template to the carbon source is (0.1-1): (0.1-1);
preferably, in step (c), the calcining temperature is 600-1200 ℃ and the calcining time is 6-24h.
Further, on the basis of the above technical scheme of the present invention, in the step (c), the second template, the carbon source and the solvent D are mixed and then separated, and the mixture obtained by separation is calcined under a protective atmosphere;
preferably, in the step (c), the solvent D includes any one or a combination of at least two of methanol, ethanol, propanol, butanol, pentanol, hexanol, acetone, toluene, N-dimethylformamide, N-hexane, cyclohexane or water.
Further, on the basis of the above technical scheme of the present invention, in the step (c), the obtained calcined material is mixed with a solvent E and then separated to remove the template;
preferably, the solvent E comprises an acidic solvent or a basic solvent;
preferably, the acidic solvent comprises any one of hydrochloric acid, sulfuric acid, nitric acid or hydrofluoric acid or a combination of at least two of the two;
preferably, the alkaline solvent comprises a potassium hydroxide solution and/or a sodium hydroxide solution.
The invention also provides a metal monatomic catalyst, and the metal monatomic catalyst is prepared by adopting the preparation method of the metal monatomic catalyst.
The invention also provides application of the metal monatomic catalyst in the field of catalytic hydrogenation.
Compared with the prior art, the invention has the following technical effects:
(1) The invention provides a preparation method of a metal monatomic catalyst, which comprises the steps of grafting a coupling agent onto a hydroxylation template to form a first template with functionalized surface, monodispersely anchoring a metal precursor on the surface of the first template through covalent bonding between a functional group carried by the coupling agent and a metal atom to form a second template with a metal precursor loaded on the surface, physically coating and isolating the metal precursor on the surface of the second template by using a carbon source with specific penetration degree, and removing the template to obtain the metal monatomic catalyst; the preparation method is based on a strategy of combining chemical confinement (dispersion anchoring) and physical confinement (coating isolation) effects, realizes uniform spatial isolation and atomic-level dispersion of a metal precursor, effectively inhibits migration and agglomeration of metal in a calcination (pyrolysis) process, greatly improves the stability of the metal monatomic catalyst, and achieves the aim of accurately and controllably preparing the metal monatomic catalyst.
(2) The invention provides a metal monatomic catalyst which is prepared by adopting the preparation method, and in view of the advantages of the preparation method, the metal monatomic catalyst has high dispersity, high catalytic activity, high selectivity and stability.
(3) The invention also provides the application of the metal monatomic catalyst, and the metal monatomic catalyst has good application prospect in the field of catalytic hydrogenation in view of the advantages of the metal monatomic catalyst.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
FIGS. 1 to 6 are high angle annular dark field image-scanning transmission electron microscopes of metal monatomic catalysts provided in examples 1 to 6 of the present invention, respectively;
FIGS. 7-14 are high angle annular dark field image-scanning transmission electron microscopes of metal monatomic catalysts provided in examples 10-17, respectively, of the present invention;
fig. 15 to 18 are high-angle annular dark field image-scanning transmission electron microscopes of the metal monatomic catalysts provided in comparative examples 1 to 4 of the present invention, respectively.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the implementation, and it should be understood that the described embodiments are some, but not all embodiments of the present 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.
According to a first aspect of the present invention, there is provided a method for preparing a metal monatomic catalyst, comprising the steps of:
(a) Providing a hydroxylated template;
mixing a hydroxylated template, a coupling agent and a solvent A, reacting, and separating to obtain a surface functionalized first template;
(b) Mixing and separating the first template, the metal precursor and the solvent B to obtain a second template with the surface loaded with the metal precursor;
(c) Mixing the second template with a carbon source, calcining under a protective atmosphere, and removing the template from the obtained calcined material to obtain the metal monatomic catalyst; wherein the penetration degree of the carbon source is 30-160/0.1mm.
Specifically, in step (a), the hydroxylated template is modified with a coupling agent that is grafted to the hydroxylated template to form a surface functionalized first template.
The hydroxylated template refers to a template having hydroxyl groups on the surface. Here, the source of the hydroxylated template is not particularly limited, and it may be purchased from an outside or may be prepared by itself.
In the step (b), the metal in the metal precursor is monodisperse on the surface of the first template by utilizing the strong covalent bonding effect between the functional group carried by the coupling agent and the metal atom, and the process realizes the uniform spatial isolation and atomic-level dispersion of the metal precursor by utilizing the chemical confinement effect (dispersion anchoring).
In the step (c), the second template and the carbon source are mixed and then calcined, the carbon source has certain viscosity, so that the metal precursor on the surface of the second template can be physically coated and isolated, the agglomeration of the metal in the post-treatment process is prevented, and the process utilizes the physical confinement effect to realize the uniform spatial isolation and atomic-level dispersion of the metal precursor, thereby effectively inhibiting the migration and agglomeration of metal atoms in the calcining (pyrolyzing) process.
The penetration degree is mainly an index representing the hardness and consistency of the carbon source (such as asphalt, vacuum residue, FCC slurry oil or formaldehyde resin, etc.) and the resistance to shear failure in the present invention, and reflects the relative viscosity of the carbon source under certain conditions. The depth of vertical penetration of the standard cone into the carbon source sample was measured as the penetration in 0.1mm at 25 ℃ and 5 seconds under a 100 g load.
Typical but non-limiting penetrations of the carbon source are 30/0.1mm, 40/0.1mm, 50/0.1mm, 60/0.1mm, 70/0.1mm, 80/0.1mm, 90/0.1mm, 100/0.1mm, 110/0.1mm, 120/0.1mm, 130/0.1mm, 140/0.1mm, 150/0.1mm or 160/0.1mm.
Because the calcined material also contains a template and an agglomerated part of metal oxide (derived from a metal precursor), the calcined material needs to be subjected to template removal and impurity removal so as to obtain the metal monatomic catalyst.
The invention provides a preparation method of a metal monatomic catalyst, which comprises the steps of grafting a coupling agent onto a hydroxylation template to form a first template with functionalized surface, monodispersely anchoring a metal precursor on the surface of the first template through covalent bonding between a functional group carried by the coupling agent and a metal atom to form a second template with a metal precursor loaded on the surface, physically coating and isolating the metal precursor on the surface of the second template by using a carbon source with specific penetration degree, and removing the template to obtain the metal monatomic catalyst; the preparation method is based on a strategy of combining chemical confinement (dispersion anchoring) and physical confinement (coating isolation) effects, realizes uniform spatial isolation and atomic-level dispersion of a metal precursor, effectively inhibits migration and agglomeration of metal in a calcination (pyrolysis) process, greatly improves the stability of the metal monatomic catalyst, and achieves the aim of accurately and controllably preparing the metal monatomic catalyst.
In addition, the chemical (dispersion anchoring) -physical (cladding isolation) dual-function domain-limiting strategy provided by the invention can be suitable for the preparation of various single-atom catalysts and has certain universality.
As an alternative embodiment of the present invention, in step (a), the method for preparing the hydroxylated template comprises the steps of:
and mixing the template, the alkaline reagent and the solvent C, and separating to obtain the hydroxylated template.
The template is used as a shape regulator to regulate the shape of the metal monatomic catalyst. The template can be removed by post-pyrolysis or acid and alkali washing.
The surface of the template is treated by the alkaline reagent, so that the density of hydroxyl on the surface of the template can be increased, more coupling agents can be grafted, and the load capacity of metal single atoms (metal precursors) can be effectively improved. The hydroxyl content of the surface of the hydroxylated template can be flexibly adjusted by the amount of the alkaline reagent.
As an alternative embodiment of the invention, the template comprises a metal oxide and/or a metal hydroxide.
By "and/or" herein is meant that the template may include only metal oxides, only metal hydroxides, or both metal oxides and metal hydroxides.
As an alternative embodiment of the present invention, the metal oxide includes any one or a combination of at least two of iron oxide, aluminum oxide, magnesium oxide, calcium oxide, titanium oxide, manganese oxide, cobalt oxide, nickel oxide, copper oxide, or zinc oxide;
preferably, the metal hydroxide includes any one of iron hydroxide, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, titanium hydroxide, manganese hydroxide, cobalt hydroxide, nickel hydroxide, copper hydroxide, or zinc hydroxide, or a combination of at least two thereof.
The alkaline reagent is mainly used for adjusting the hydroxyl content on the template. As an alternative embodiment of the present invention, the alkaline agent comprises any one of sodium hydroxide, potassium hydroxide, sodium acetate, sodium carbonate, potassium amide, sodium hydride or potassium hydride or a combination of at least two thereof.
As an alternative embodiment of the present invention, the solvent C includes any one of methanol, ethanol, propanol, butanol, pentanol, hexanol, acetone, toluene, N-dimethylformamide, N-hexane, cyclohexane or water or a combination of at least two thereof.
As an alternative embodiment of the invention, the mass ratio of the template to the alkaline agent is (0.1-1): (0.1-1). The template and alkaline agent are typically, but not limited to, in a mass ratio of 0.1:0.1, 0.1:0.2, 0.1:0.4, 0.1:0.5, 0.1:0.6, 0.1:0.8, 0.1: 1. 0.2:0.1, 0.3:0.1, 0.4:0.1, 0.5:0.1, 0.6:0.1, 0.8:0.1 or 1:0.1.
preferably, the mass ratio of the template, the alkaline agent and the solvent C is (0.1-1): (0.1-10): (10-100).
Through the limitation of the specific types and the dosage of the template, the alkaline reagent and the solvent C, the surface of the template is rich in hydroxyl, so that more silane coupling agents are further grafted and separated from each other, and the function of regulating and controlling the metal content of the monatomic catalyst can be achieved.
As an alternative embodiment of the present invention, in the step (a), the coupling agent includes any one or a combination of at least two of an amino group-containing silane coupling agent, a mercapto group-containing silane coupling agent, or a phosphoric acid group-containing silane coupling agent, and preferably includes an amino group-containing silane coupling agent;
preferably, the amino group-containing silane coupling agent includes any one of 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N- (beta-aminoethyl) -gamma-aminopropyltriethoxysilane, 3-aminopropyldimethylmethoxysilane, ethylenediamine-methyltriethoxysilane, or 3-2- (aminoethyl) aminopropyltrimethoxysilane, or a combination of at least two thereof.
Preferably, the mercapto group-containing silane coupling agent includes any one of 3-mercaptopropyl (dimethoxy) silane, (3-mercaptopropyl) triethoxysilane, (3-mercaptopropyl) trimethoxysilane, or a combination of at least two thereof.
Preferably, the silane coupling agent containing a phosphoric acid group includes tris (trimethylsilyl) phosphate.
The specific grafting of the coupling agent on the surface of the hydroxylated template is easier to realize by limiting the specific type of the coupling agent. Meanwhile, metal monatomic catalysts such as M-N-C, M-S-C, M-P-C, M-N-S-C and M-N-P-C (M is metal such as Co, fe, mn or Cu) can be synthesized by adjusting the terminal group types (such as amino, sulfydryl, phosphate group and the like) of the silane coupling agent, so that the fine structure of the monatomic catalyst can be accurately regulated and controlled.
The solvent A species is selected to have good compatibility with the hydroxylated template and the coupling agent. As an alternative embodiment of the present invention, in the step (a), the solvent a includes any one or a combination of at least two of methanol, ethanol, propanol, butanol, pentanol, hexanol, acetone, toluene, N-dimethylformamide, N-hexane, cyclohexane or water.
As an alternative embodiment of the present invention, in step (a), the mass ratio of the hydroxylated template, the coupling agent and the solvent A is (0.1-1): (0.1-1): (10-100); the hydroxylated template, coupling agent and solvent a are typically, but not limited to, used in a ratio of 0.1:0.1: 10. 0.2:0.1: 10. 0.5:0.1: 10. 0.8:0.1: 10. 1:0.1: 10. 0.1:0.5: 10. 0.1:1: 10. 0.3:0.5: 10. 0.3:1: 10. 0.5:0.5: 10. 0.5:1: 10. 0.8:0.5: 10. 1:0.5: 10. 0.1:0.1: 20. 0.1:0.1: 40. 0.1:0.1: 50. 0.1:0.1: 60. 0.1:0.1: 80. 0.1:0.1: 100. 0.5:0.1: 20. 0.5:0.1: 40. 0.5:0.1: 50. 0.5:0.1: 60. 0.5:0.1: 80. 0.5:0.1: 100. 1:0.1: 20. 1:0.2: 40. 1:0.5: 50. 1:0.5: 60. 1:1:80 or 1:1:100.
the metal content in the metal monatomic catalyst can be effectively adjusted by adjusting the dosage of the alkaline reagent and the dosage of the coupling agent in the preparation process of the hydroxylated template.
As an alternative embodiment of the present invention, in step (a), the reaction temperature is 0-120 ℃ and the reaction time is 4-24 hours. Typical, but not limiting, reaction temperatures are 0 deg.C, 10 deg.C, 20 deg.C, 30 deg.C, 40 deg.C, 50 deg.C, 60 deg.C, 70 deg.C, 80 deg.C, 90 deg.C, 100 deg.C, 110 deg.C or 120 deg.C. Typical but non-limiting reaction times are 4h, 5h, 6h, 8h, 10h, 12h, 14h, 15h, 16h, 18h, 20h, 22h or 24h.
As an alternative embodiment of the present invention, in the step (b), the metal precursor includes any one of manganese salt, iron salt, cobalt salt, nickel salt, copper salt, zinc salt or chromium salt or a combination of at least two of them.
By selecting cheap metal salts of specific types as metal precursors, expensive ligands such as phthalocyanine and porphyrin are not needed for coordination, and the preparation can be carried out at lower cost.
As an alternative embodiment of the present invention, in the step (B), the solvent B includes any one or a combination of at least two of methanol, ethanol, propanol, butanol, pentanol, hexanol, acetone, toluene, N-dimethylformamide, N-hexane, cyclohexane or water.
As an alternative embodiment of the present invention, in the step (B), the mass ratio of the first template, the metal precursor and the solvent B is (1-5): (0.1-1): (10-100); the following is a typical but non-limiting ratio of.
The dosage ratio of the first template, the metal precursor and the solvent B is further limited, so that the metal precursor is monodispersely immobilized on the surface of the first template, and the metal content in the monatomic catalyst can be regulated and controlled through the step.
As an alternative embodiment of the present invention, in step (b), the temperature of mixing is 0-80 ℃ and the time of mixing is 4-24h. Typical but not limiting mixing temperatures are 0 ℃, 10 ℃, 20 ℃, 30 ℃, 40 ℃, 50 ℃,60 ℃, 70 ℃ or 80 ℃, and typical but not limiting mixing times are 4h, 5h, 6h, 8h, 10h, 12h, 14h, 15h, 16h, 18h, 20h, 22h or 24h.
The carbon source is usually a viscous carbide having coating ability. As an alternative embodiment of the present invention, in step (c), the carbon source comprises any one of asphalt, vacuum residue, FCC slurry oil or formaldehyde resin or a combination of at least two thereof, preferably asphalt.
The specific type of the carbon source is limited, so that the metal precursor which is monodisperse on the surface of the first template is not agglomerated in the calcining process, and the metal is physically isolated.
As a preferred embodiment of the present invention, the asphalt comprises petroleum asphalt and/or coal asphalt.
Preferably, petroleum asphalt is adopted as a carbon source, and the petroleum asphalt has the advantages of unique property when used for synthesizing carbon materials: firstly, the cost is low, and the material is cheap and easy to obtain, thereby meeting the new trend of material synthesis; and secondly, a large amount of carbon-containing polycyclic hydrocarbons enable the petroleum asphalt to be used as an ideal raw material to obtain a carbon material with high graphitization degree, and heteroatom doping is performed, so that compared with MOF and ZIF-based carbon materials, the carbonized carbon residue value is higher, the morphology is easy to control, and no other heteroatom residues are left after carbonization.
As an alternative embodiment of the present invention, in the step (c), the mass ratio of the second template to the carbon source is (0.1-1): (0.1-1); the typical but non-limiting mass ratio of the second template to the carbon source is 0.1:0.1, 0.1:0.2, 0.1:0.4, 0.1:0.5, 0.1:0.8, 0.1: 1. 0.2:0.1, 0.4:0.1, 0.5:0.1, 0.6:0.1, 0.8:0.1 or 1:0.1.
as an alternative embodiment of the present invention, in step (c), the calcination temperature is 600-1200 ℃ and the calcination time is 6-24h. Typical but non-limiting temperatures for calcination are 600 ℃, 700 ℃,800 ℃,900 ℃, 1000 ℃, 1100 ℃ or 1200 ℃. Typical but non-limiting calcination times are 6h, 8h, 10h, 12h, 14h, 15h, 16h, 18h, 20h, 22h or 24h.
The calcination temperature will affect the nitrogen (or phosphorus, sulfur) doping content and its existing structure in the metal monatomic catalyst, further affecting the distribution and composition of the metal atoms. The calcination temperature is too low, nitrogen (or phosphorus and sulfur) can not be effectively doped into a carbon skeleton, so that single atoms can not be effectively stabilized, the calcination temperature is too high, the cliff type reduction of the nitrogen (or phosphorus and sulfur) content can be caused, and the single atoms are easy to agglomerate at high temperature. Therefore, the temperature for calcination is preferably limited to a specific value range.
In the step (c), the second template and the carbon source need to be uniformly mixed, and a dry mixing mode or a wet mixing mode can be adopted. As an alternative embodiment of the present invention, in the step (c), the second template, the carbon source and the solvent D are mixed and separated, and the separated mixture is calcined under a protective atmosphere to obtain the calcined material.
The above materials are mixed with solvent D to achieve thorough mixing of the second template and the carbon source. This wet mixing method is preferable for using a viscous substance such as pitch as a carbon source.
As an alternative embodiment of the present invention, in the step (c), the solvent D includes any one of methanol, ethanol, propanol, butanol, pentanol, hexanol, acetone, toluene, N-dimethylformamide, N-hexane, cyclohexane or water or a combination of at least two thereof.
As an alternative embodiment of the present invention, in the step (c), the obtained calcined material is mixed with a solvent E and then separated to be de-templated;
as an alternative embodiment of the present invention, in step (c), the solvent E comprises an acidic solvent or a basic solvent;
preferably, the acidic solvent comprises any one of hydrochloric acid, sulfuric acid, nitric acid or hydrofluoric acid or a combination of at least two of the two;
preferably, the alkaline solvent comprises a potassium hydroxide solution and/or a sodium hydroxide solution.
The specific kind of the solvent E is limited, so that the template and agglomerated partial metal oxide in the calcined material can be effectively removed, and the purity of the metal monatomic catalyst is further improved.
According to the second aspect of the invention, the invention also provides a metal monatomic catalyst prepared by the preparation method of the metal monatomic catalyst.
In view of the advantages of the preparation method of the metal monatomic catalyst, the prepared metal monatomic catalyst has a controllable morphology and a structure that metal is distributed on the surface of the catalyst or in the pore channels in a monatomic dispersion mode, so that the metal monatomic catalyst has the characteristics of high dispersion degree, high catalytic activity, high selectivity and stability. Meanwhile, the metal monatomic catalyst has lower preparation cost.
According to the third aspect of the invention, the application of the metal monatomic catalyst in the field of catalytic hydrogenation is also provided.
In view of the advantages of the metal monatomic catalyst, the metal monatomic catalyst has wide application prospects in the fields of catalytic hydrogenation and the like.
The present invention will be further described with reference to specific examples and comparative examples.
Example 1
The embodiment provides a preparation method of a Co-N-C metal monatomic catalyst, which comprises the following steps:
(a) Providing a hydroxylated template: ultrasonically dispersing 5.61g of alkaline reagent (sodium hydroxide) in 200mL of absolute ethyl alcohol, adding 2g of template (sheet magnesium oxide), ultrasonically dispersing for 1h, then stirring for 6h at 25 ℃, filtering and washing a precipitate with absolute ethyl alcohol, and freeze-drying for 24h at minus 55 ℃ to obtain a hydroxylated template (hydroxylated magnesium oxide);
dispersing 1.0g of hydroxylated template in 200mL of solvent A (absolute ethyl alcohol), ultrasonically dispersing for 1h, slowly dropwise adding 0.5mL of coupling agent (3-aminopropyltriethoxysilane), violently stirring at 60 ℃ for reacting for 6h, filtering the precipitate, washing with absolute ethyl alcohol, and freeze-drying for 24h to obtain a surface functionalized first template (surface aminated magnesium oxide);
(b) Weighing 1.0g of a first template, ultrasonically dispersing the first template in 200mL of a solvent B (absolute ethyl alcohol), dropwise adding 20mL of a metal precursor solution (absolute ethyl alcohol solution containing cobalt chloride hexahydrate) with the concentration of 30mmol/L, stirring and adsorbing at room temperature for 6 hours, filtering and washing the obtained mixed solution, and freeze-drying at minus 55 ℃ for 24 hours to obtain a second template (magnesium oxide with cobalt chloride hexahydrate loaded on the surface) with a metal precursor loaded on the surface;
(c) Weighing 0.25g of carbon source petroleum asphalt (the main components comprise 18.63 wt% of saturation component, 30.13 wt% of aromatic component, 37.21 wt% of colloid and 7.40 wt% of asphaltene, and the needle penetration is 70/0.1 mm), dispersing in 30mL of solvent D (toluene), adding 1.0g of a second template, ultrasonically dispersing for 1h, then evaporating and recovering the toluene at 90 ℃ through a reduced pressure distillation device, grinding the separated mixture, placing the ground mixture in a quartz boat, placing the quartz boat with the mixture in a tube furnace, calcining at the temperature rise rate of 5 ℃/min and calcining at the temperature of 800 ℃ for 3h, and obtaining a calcined material (a mixture of magnesium oxide and a porous carbon composite material doped with cobalt/nitrogen);
placing the calcined material in 150mL of 1mol/L solvent E (HCl solution) and stirring for 12h at room temperature, stirring for 12h at 90 ℃, removing a magnesium oxide template and agglomerated partial cobalt oxide, filtering, washing with water to be neutral, and freeze-drying for 24h to obtain the Co-N-C metal monatomic catalyst with the two-dimensional flaky morphology.
Example 2
This example provides a method for preparing a Co-N-C metal monoatomic catalyst, which comprises the same steps and process parameters as in example 1, except that the carbon source in step (C) was replaced with petroleum asphalt, which was a vacuum residue having a main composition comprising 10.1wt.% saturates, 40.3wt.% aromatics, 40.2wt.% gums and 9.4wt.% asphaltenes, and having a penetration of 70/0.1 mm.
Example 3
This example provides a method for preparing a Co-N-C metal monatomic catalyst, which was identical to example 1 except that the carbon source in step (C) was replaced with petroleum pitch, which had a main composition of 12.8wt.% saturates, 67.5wt.% aromatics, 15.1wt.% gums and 4.6wt.% asphaltenes, and a penetration of 160/0.1mm, and the process parameters were the same as in example 1.
Example 4
This example provides a method for preparing a Co-N-C metal monatomic catalyst, which was the same as in example 1 except that the calcination temperature in step (C) was 600 ℃ and the other steps and process parameters were the same.
Example 5
This example provides a method for preparing a Co-N-C metal monatomic catalyst, which was the same as in example 1 except that the calcination temperature in step (C) was 1200 ℃.
Example 6
This example provides a method for preparing a Co-N-C metal monatomic catalyst, which was the same as in example 1 except that the calcination temperature in step (C) was 1250 deg.C.
Example 7
This example provides a method for preparing a Co-N-C metal monatomic catalyst, which was the same as in example 1 except that the mass of the alkali agent (sodium hydroxide) in step (a) was 56.1g, and the remaining steps and process parameters were the same.
Example 8
This example provides a method for preparing a Co-N-C metal monatomic catalyst, which was the same as in example 1, except that the mass of the alkali agent (sodium hydroxide) in step (a) was 0.2g, and the remaining steps and process parameters were the same.
Example 9
This example provides a method for preparing a Co-N-C metal monatomic catalyst, which was the same as in example 1 except that the mass of the alkali agent (sodium hydroxide) in step (a) was 0.1g, and the remaining steps and process parameters were the same.
Example 10
This example provides a method for preparing a Co-N-C metal monoatomic catalyst, which comprises the same steps and process parameters as in example 1, except that the penetration of petroleum asphalt in step (C), which comprises 13.8wt.% saturates, 30.6wt.% aromatics, 40.2wt.% gums and 15.4wt.% asphaltenes, was 30/0.1 mm.
Example 11
This example provides a method for preparing a Co-N-C metal monatomic catalyst, which was the same as in example 1 except that the mass of the petroleum pitch in step (C) was 2g, and the remaining steps and process parameters were the same.
Example 12
This example provides a method for preparing a Mn-N-C metal monatomic catalyst, comprising the steps of:
(a) Providing a hydroxylated template: ultrasonically dispersing 5.61g of alkaline reagent (potassium hydroxide) into 200mL of absolute ethyl alcohol, adding 2g of template (sheet magnesium oxide), ultrasonically dispersing for 1h, then stirring for 6h at 25 ℃, filtering and washing a precipitate with absolute ethyl alcohol, and freeze-drying for 24h to obtain a hydroxylated template (hydroxylated magnesium oxide);
dispersing 1.0g of hydroxylated template in 200mL of solvent A (absolute ethyl alcohol), ultrasonically dispersing for 1h, slowly dropwise adding 1.5mL of coupling agent (3-aminopropyltriethoxysilane), violently stirring at 60 ℃ for reacting for 6h, filtering the precipitate, washing with absolute ethyl alcohol, and freeze-drying for 24h to obtain a surface functionalized first template (surface aminated magnesium oxide);
(b) Weighing 1.0g of a first template, ultrasonically dispersing the first template in 200mL of a solvent B (absolute ethyl alcohol), dropwise adding 20mL of a metal precursor solution (an absolute ethyl alcohol solution containing manganese chloride) with the concentration of 50mmol/L, stirring and adsorbing at room temperature for 6 hours, filtering and washing the obtained mixed solution, and freeze-drying for 24 hours to obtain a second template (magnesium oxide of which the surface is loaded with manganese chloride) of which the surface is loaded with a metal precursor;
(c) Weighing 0.2g of carbon source petroleum asphalt (the main components of the petroleum asphalt comprise 18.63 wt% of saturated component, 30.13 wt% of aromatic component, 37.21 wt% of colloid and 7.40 wt% of asphaltene, and the penetration degree is 70/0.1 mm), dispersing in 30mL of solvent D (toluene), adding 1.0g of a second template, ultrasonically dispersing for 1h, then evaporating and recovering the toluene at 90 ℃ through a reduced pressure distillation device, grinding the separated mixture, placing the ground mixture in a quartz boat, placing the quartz boat with the mixture in a tube furnace, calcining in a nitrogen atmosphere at the heating rate of 5 ℃/min and at 900 ℃ for 3h, and obtaining a calcined material (a mixture of magnesium oxide and a porous carbon composite material doped with manganese/nitrogen);
and (3) placing the calcined material into 150mL of 1mol/L solvent E (HCl solution), stirring for 12h at room temperature, stirring for 12h at 90 ℃, removing a magnesium oxide template and agglomerated partial manganese oxide, filtering, washing with water to be neutral, and freeze-drying for 24h at minus 55 ℃ to obtain the Mn-N-C metal monatomic catalyst with the two-dimensional flaky morphology.
Example 13
This example provides a method for preparing a Fe-N-C metal monatomic catalyst, comprising the following steps:
(a) Providing a hydroxylated template: ultrasonically dispersing 8.0g of alkaline reagent (sodium hydroxide) in 200mL of absolute ethyl alcohol, adding 2g of template (sheet magnesium hydroxide), ultrasonically dispersing for 1h, then stirring for 6h at 40 ℃, filtering a precipitate, washing with absolute ethyl alcohol, and freeze-drying for 24h to obtain a hydroxylated template (hydroxylated magnesium hydroxide);
dispersing 1.0g of hydroxylated template in 200mL of solvent A (absolute ethyl alcohol), ultrasonically dispersing for 1h, slowly dropwise adding 1.0mL of coupling agent (N- (beta-aminoethyl) -gamma-aminopropyltriethoxysilane), violently stirring at 80 ℃ for reacting for 8h, filtering the precipitate, washing with absolute ethyl alcohol, and freeze-drying for 24h to obtain a surface functionalized first template (surface aminated magnesium hydroxide);
(b) Weighing 1.0g of a first template, ultrasonically dispersing the first template in 200mL of a solvent B (absolute ethyl alcohol), dropwise adding 20mL of a metal precursor solution (absolute ethyl alcohol solution containing ferric nitrate) with the concentration of 70mmol/L, stirring and adsorbing at room temperature for 6 hours, filtering and washing the obtained mixed solution, and freeze-drying for 24 hours to obtain a second template (magnesium hydroxide with ferric nitrate loaded on the surface) with a metal precursor loaded on the surface;
(c) Weighing 0.3g of carbon source petroleum asphalt (the main components of the petroleum asphalt comprise 18.63 wt% of saturated component, 30.13 wt% of aromatic component, 37.21 wt% of colloid and 7.40 wt% of asphaltene, and the penetration degree is 70/0.1 mm), dispersing in 30mL of solvent D (toluene), adding 1.0g of a second template, ultrasonically dispersing for 1h, then evaporating and recovering the toluene at 90 ℃ through a reduced pressure distillation device, grinding the separated mixture, placing the ground mixture in a quartz boat, placing the quartz boat with the mixture in a tube furnace, calcining at the temperature rise rate of 5 ℃/min and at the temperature of 800 ℃ for 2h in a nitrogen atmosphere to obtain a calcined material (a mixture of magnesium hydroxide and a porous carbon composite material doped with iron/nitrogen);
and (3) placing the calcined material into 150mL of 1mol/L solvent E (HCl solution), stirring for 12h at room temperature, stirring for 12h at 90 ℃, removing the magnesium hydroxide template, filtering, washing with water to be neutral, and freeze-drying for 36h to obtain the Fe-N-C metal monatomic catalyst with the two-dimensional lamellar morphology structure.
Example 14
The embodiment provides a preparation method of a Ni-N-C metal monatomic catalyst, which comprises the following steps:
(a) Providing a hydroxylated template: preparing 200mL of 2mol/L aqueous solution containing an alkaline reagent (sodium acetate), adding 2g of a template (spherical titanium dioxide, the average particle size is 50 nm), ultrasonically dispersing for 1h, then stirring for 6h at 25 ℃, filtering a precipitate, washing with absolute ethyl alcohol, and freeze-drying for 24h to obtain a hydroxylated template (hydroxylated titanium dioxide);
dispersing 1.0g of a hydroxylated template in 200mL of a solvent A (absolute ethyl alcohol), ultrasonically dispersing for 1h, slowly dropwise adding 1.5mL of a coupling agent (3-aminopropyl dimethyl methoxy silane), violently stirring at 120 ℃ for reacting for 6h, filtering a precipitate, washing with absolute ethyl alcohol, and freeze-drying for 24h to obtain a surface functionalized first template (surface aminated titanium dioxide);
(b) Weighing 1.0g of a first template, ultrasonically dispersing the first template in 200mL of solvent B (deionized water), dropwise adding 20mL of metal precursor solution (deionized water solution containing nickel chloride) with the concentration of 50mmol/L, stirring and adsorbing for 6 hours at room temperature, filtering and washing the obtained mixed solution, and freeze-drying for 24 hours at minus 55 ℃ to obtain a second template (titanium dioxide with nickel chloride loaded on the surface) with a metal precursor loaded on the surface;
(c) Weighing 0.5g of carbon source petroleum asphalt (the main components comprise 18.63 wt% of saturated component, 30.13 wt% of aromatic component, 37.21 wt% of colloid and 7.40 wt% of asphaltene, and the penetration degree is 70/0.1 mm), dispersing in 30mL of solvent D (toluene), adding 1.0g of second template, ultrasonically dispersing for 1h, then evaporating and recovering the toluene at 90 ℃ through a reduced pressure distillation device, grinding the separated mixture, placing the ground mixture in a quartz boat, placing the quartz boat with the mixture in a tube furnace, calcining in a nitrogen atmosphere, heating at a rate of 5 ℃/min, and calcining at 800 ℃ for 2h to obtain a calcined material (a mixture of titanium dioxide and a porous carbon composite material doped with nickel/nitrogen);
placing the calcined material into 150mL of 1mol/L solvent E (HF solution) and stirring at room temperature for 12h and at 90 ℃ for 12h, removing the iron oxide template and the agglomerated partial nickel oxide, filtering, washing with water to be neutral, and freeze-drying for 24h to obtain the Ni-N-C metal monatomic catalyst.
Example 15
The embodiment provides a preparation method of a Cu-N-C metal monatomic catalyst, which comprises the following steps:
(a) Providing a hydroxylated template: preparing 200mL of a 3mol/L alkaline reagent (sodium carbonate) aqueous solution, adding 2g of a template (flaky titanium dioxide), ultrasonically dispersing for 1h, then stirring for 6h at 25 ℃, filtering a precipitate, washing with absolute ethyl alcohol, and freeze-drying for 24h to obtain a hydroxylated template (hydroxylated titanium dioxide);
dispersing 1.0g of a hydroxylated template in 200mL of a solvent A (absolute ethyl alcohol), ultrasonically dispersing for 1h, slowly dropwise adding 2mL of a coupling agent (3-2- (aminoethyl) aminopropyltrimethoxysilane), violently stirring at 80 ℃ for reacting for 6h, filtering a precipitate, washing with absolute ethyl alcohol, and freeze-drying for 24h to obtain a surface functionalized first template (surface aminated titanium dioxide);
(b) Weighing 1.0g of a first template, ultrasonically dispersing the first template in 200mL of solvent B (deionized water), dropwise adding 20mL of metal precursor solution (deionized water solution containing copper chloride) with the concentration of 70mmol/L, stirring and adsorbing at room temperature for 6 hours, filtering and washing the obtained mixed solution, and freeze-drying for 24 hours to obtain a second template (titanium dioxide with copper chloride loaded on the surface) with a metal precursor loaded on the surface;
(c) Weighing 0.25g of carbon source petroleum asphalt (the main components comprise 18.63 wt% of saturated component, 30.13 wt% of aromatic component, 37.21 wt% of colloid and 7.40 wt% of asphaltene, and the penetration degree is 70/0.1 mm), dispersing in 30mL of solvent D (toluene), adding 1.0g of second template, ultrasonically dispersing for 1h, then evaporating and recovering the toluene at 90 ℃ through a reduced pressure distillation device, grinding the separated mixture, placing the ground mixture in a quartz boat, placing the quartz boat with the mixture in a tube furnace, calcining in a nitrogen atmosphere, heating at a rate of 5 ℃/min, and calcining at 800 ℃ for 3h to obtain a calcined material (a mixture of titanium dioxide and a porous carbon composite material doped with copper/nitrogen);
and (3) placing the calcined material into 150mL of 1mol/L solvent E (HF solution), stirring for 24h at room temperature, stirring for 12h at 90 ℃, removing a titanium dioxide template and agglomerated partial copper oxide, filtering, washing with water to be neutral, and freeze-drying for 24h to obtain the Cu-N-C metal monatomic catalyst.
Example 16
This example provides a method for preparing a Co-S-C metal monatomic catalyst, which was the same as in example 1, except that the coupling agent in step (a) was replaced with 3-mercaptopropyl (dimethoxy) silane instead of 3-aminopropyltriethoxysilane.
Example 17
This example provides a method for preparing a Co-P-C metal monatomic catalyst, which was the same as in example 1, except that the coupling agent in step (a) was replaced with tris (trimethylsilyl) phosphate from 3-aminopropyltriethoxysilane.
Comparative example 1
This comparative example provides a method for preparing a Co-N-C metal monatomic catalyst, which was the same as in example 1 except that a coupling agent was not added in step (a), but the obtained hydroxylated template was directly substituted for the first template in step (b), and the remaining steps and process parameters were the same.
Comparative example 2
This comparative example provides a method for preparing a Co-N-C metal monatomic catalyst, which was the same as in example 1 except that the template was not subjected to hydroxylation treatment in step (a), but was directly mixed with a coupling agent and a solvent A.
Comparative example 3
This comparative example provides a method for preparing a Co-N-C metal monoatomic catalyst, which was the same as example 1 except that the carbon source in step (C) was replaced with glucose, and the remaining steps and process parameters were the same as those of example 1.
Comparative example 4
This comparative example provides a method for preparing a Co-N-C metal monoatomic catalyst, which has the same steps and process parameters as example 1, except that the penetration of petroleum asphalt in step (C), whose main components include 35.62wt.% saturates, 27.17wt.% aromatics, 18.43wt.% gums, and 18.78wt.% asphaltenes, was 20/0.1 mm.
To verify the technical effects of the examples and comparative examples, the following experiments were conducted.
Experimental example 1
The catalysts provided in examples 1 to 6, examples 10 to 17 and comparative examples 1 to 4 were subjected to high-angle toroidal dark-field image-scanning transmission electron microscopy, and the results are shown in fig. 1 to 18.
As can be seen from fig. 1 to 14, the metal elements are in a monodisperse state in the catalyst and have no significant aggregation, indicating the successful synthesis of the monatomic catalyst synthesized by the technical scheme and having high dispersity. As can be seen from fig. 15, the catalyst synthesized without adding the silane coupling agent tends to generate nanoclusters during calcination, resulting in a catalyst in which metal monoatomic atoms coexist with nanoclusters. As can be seen in fig. 16, the monatomic catalyst was also obtained without hydroxylation of the template, except for the lower metal loading. As can be seen in fig. 17, the metal nanocluster catalyst is formed after calcination using glucose without viscosity as a carbon source. As can be seen from fig. 18, when low-viscosity petroleum asphalt is used as a carbon source, a metal catalyst in which a single atom and nanoclusters coexist is formed after calcination, and the atom utilization rate cannot be maximized, so that it is difficult to exert the most excellent catalytic performance.
Experimental example 2
The catalytic performance and the like of the metal monatomic catalysts provided in examples 1 to 17 and comparative examples 1 to 4 were examined. Wherein the stability detection method is used for catalytic hydrogenation reaction for ten times without any treatment step, and the catalytic performance detection method comprises measuring 20mL of 5mM reaction substrate nitroaromatic aqueous solution, injecting the aqueous solutionIn a small reaction bottle, the reaction bottle is placed under the ultrasonic environment, 2mg of catalyst and 47.3mg of NaBH reducing agent are weighed 4 And adding into a reaction bottle. And transferring the reaction bottle to a constant-temperature water bath, controlling the temperature to be 30 ℃ to start reaction, and starting timing. During the reaction, a part of the reaction mixture is sucked out by a needle tube, and the reactants and the products are detected in real time by UV-Vis. Specific results are shown in table 1.
TABLE 1
As can be seen from the data in Table 1, the preparation method of the metal monatomic catalyst provided by the invention has excellent catalytic activity and stability when the catalyst prepared from different metals is applied to catalytic hydrogenation reaction, and meanwhile, the morphology of the monatomic catalyst can be regulated and controlled through the morphology of the template, the monatomic catalyst is also compatible with different carbon sources, the performance of the monatomic catalyst anchored by different groups is also excellent, the influence of different calcination temperatures on the catalytic performance is larger, and the catalytic performance can be regulated by regulating and controlling the alkali treatment concentration; on the contrary, the catalytic performance, selectivity and stability of the catalyst which is not subjected to hydroxylation or amino modification in the comparative example are greatly reduced, which shows that the hydroxyl and amino have a crucial influence on the loading amount of the metal active center, the low-penetration petroleum asphalt and the non-viscous glucose are used as carbon sources, the catalytic performance is greatly reduced, which shows that the viscosity of the carbon source is particularly important for the stability of the metal monoatomic atom, the coating and isolating effects of the lower or non-viscous carbon source are poor, and the metal atom tends to agglomerate to generate a part of metal nanoclusters in the calcining process, so that the catalytic performance is greatly reduced. The metal content and the existing form (single atom or cluster) of the catalyst can be regulated by regulating the density of hydroxyl and amino on the surface of the template, so that the catalytic performance of the catalyst is influenced. The results show that the metal monatomic catalyst prepared by the preparation method has good universality and controllability.
Further, the results of examining the multiplexing performance of the metal monatomic catalyst provided by the present invention, as represented by example 1, are shown in table 2.
Table 2 example 1 cyclic reusability of metal monatomic catalysts
As can be seen from the data in Table 2, the metal monatomic catalyst provided by the embodiment of the invention has excellent cycle stability, and the performance of the metal monatomic catalyst remains unchanged after 10 times of reuse, so that a good practical application prospect is shown.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and these modifications or substitutions do not depart from the spirit of the corresponding technical solutions of the embodiments of the present invention.
Claims (6)
1. A preparation method of a metal monatomic catalyst is characterized by comprising the following steps:
(a) Providing a hydroxylated template;
mixing a hydroxylated template, a coupling agent and a solvent A, reacting, and separating to obtain a surface functionalized first template;
in the step (a), the coupling agent comprises any one of or a combination of at least two of an amino-containing silane coupling agent, a mercapto-containing silane coupling agent or a phosphoric acid group-containing silane coupling agent;
in the step (a), the solvent A comprises any one or a combination of at least two of methanol, ethanol, propanol, butanol, pentanol, hexanol, acetone, toluene, N-dimethylformamide, N-hexane, cyclohexane or water;
in the step (a), the mass ratio of the hydroxylated template to the coupling agent to the solvent A is (0.1-1): (0.1-1): (10-100);
in the step (a), the reaction temperature is 0-120 ℃, and the reaction time is 4-24h;
in the step (a), the preparation method of the hydroxylated template comprises the following steps: mixing the template, an alkaline reagent and a solvent C, and separating to obtain a hydroxylated template;
wherein: the template comprises a metal oxide and/or a metal hydroxide;
the metal oxide comprises any one of iron oxide, aluminum oxide, magnesium oxide, calcium oxide, titanium oxide, manganese oxide, cobalt oxide, nickel oxide, copper oxide or zinc oxide or a combination of at least two of the iron oxide, the aluminum oxide, the magnesium oxide, the calcium oxide, the titanium oxide, the manganese oxide, the cobalt oxide, the nickel oxide and the copper oxide;
the metal hydroxide comprises any one or the combination of at least two of ferric hydroxide, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, titanium hydroxide, manganese hydroxide, cobalt hydroxide, nickel hydroxide, copper hydroxide or zinc hydroxide;
and/or the alkaline reagent comprises any one or the combination of at least two of sodium hydroxide, potassium carbonate, sodium carbonate, amino potassium, amino sodium, sodium hydride or potassium hydride;
and/or, the solvent C comprises any one or a combination of at least two of methanol, ethanol, propanol, butanol, pentanol, hexanol, acetone, toluene, N-dimethylformamide, N-hexane, cyclohexane or water;
and/or the mass ratio of the template to the alkaline reagent to the solvent C is (0.1-1): (0.1-10): (10-100);
(b) Mixing and separating the first template, the metal precursor and the solvent B to obtain a second template with the surface loaded with the metal precursor;
in the step (b), the metal precursor comprises any one of manganese salt, iron salt, cobalt salt, nickel salt, copper salt, zinc salt or chromium salt or the combination of at least two of the manganese salt, the iron salt, the cobalt salt, the nickel salt, the copper salt, the zinc salt or the chromium salt;
in the step (B), the solvent B comprises any one or a combination of at least two of methanol, ethanol, propanol, butanol, pentanol, hexanol, acetone, toluene, N-dimethylformamide, N-hexane, cyclohexane or water;
in the step (B), the mass ratio of the first template to the metal precursor to the solvent B is (1-5): (0.1-1): (10-100);
in the step (b), the mixing temperature is 0-80 ℃, and the mixing time is 4-24h;
(c) Mixing the second template with a carbon source, calcining under a protective atmosphere, and de-templating the obtained calcined material to obtain a metal monatomic catalyst; wherein the penetration degree of the carbon source is 30-160/0.1mm;
in step (c), the carbon source comprises any one or a combination of at least two of asphalt, vacuum residue, FCC slurry oil or formaldehyde resin;
and/or, the carbon source comprises pitch, the pitch comprises petroleum pitch and/or coal pitch;
in the step (c), the mass ratio of the second template to the carbon source is (0.1-1): (0.1-1);
in the step (c), the calcining temperature is 600-1200 ℃, and the calcining time is 6-24h.
2. The method according to claim 1, wherein the amino group-containing silane coupling agent comprises any one or a combination of at least two of 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N- (β -aminoethyl) - γ -aminopropyltriethoxysilane, 3-aminopropyldimethylmethoxysilane, ethylenediamine methyltriethoxysilane, and 3-2- (aminoethyl) aminopropyltrimethoxysilane;
and/or, the mercapto-containing silane coupling agent comprises any one of 3-mercaptopropyl (dimethoxy) silane, (3-mercaptopropyl) triethoxysilane, (3-mercaptopropyl) trimethoxysilane or a combination of at least two of the two;
and/or the silane coupling agent containing phosphoric acid groups comprises tris (trimethylsilyl) phosphate.
3. The method according to claim 1, wherein in the step (c), the second template, the carbon source and the solvent D are mixed, separated, and the separated mixture is calcined under a protective atmosphere;
in the step (c), the solvent D includes any one or a combination of at least two of methanol, ethanol, propanol, butanol, pentanol, hexanol, acetone, toluene, N-dimethylformamide, N-hexane, cyclohexane or water.
4. The production method according to any one of claims 1 to 3, characterized in that, in the step (c), the obtained calcined material is separated after being mixed with a solvent E to be demoulded;
the solvent E comprises an acidic solvent or a basic solvent;
the acidic solvent comprises any one or the combination of at least two of hydrochloric acid, sulfuric acid, nitric acid or hydrofluoric acid;
the alkaline solvent comprises a potassium hydroxide solution and/or a sodium hydroxide solution.
5. A metal monoatomic catalyst produced by the method for producing a metal monoatomic catalyst according to any one of claims 1 to 4.
6. Use of the metal monatomic catalyst according to claim 5 in the field of catalytic hydrogenation.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110258913.3A CN112973759B (en) | 2021-03-10 | 2021-03-10 | Preparation method of metal monatomic catalyst, metal monatomic catalyst and application |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110258913.3A CN112973759B (en) | 2021-03-10 | 2021-03-10 | Preparation method of metal monatomic catalyst, metal monatomic catalyst and application |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112973759A CN112973759A (en) | 2021-06-18 |
| CN112973759B true CN112973759B (en) | 2022-11-25 |
Family
ID=76336257
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110258913.3A Active CN112973759B (en) | 2021-03-10 | 2021-03-10 | Preparation method of metal monatomic catalyst, metal monatomic catalyst and application |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112973759B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114068960A (en) * | 2021-10-25 | 2022-02-18 | 黑龙江大学 | 3D porous spherical carbon shell-supported transition metal monatomic catalyst and preparation method and application thereof |
| CN114225932A (en) * | 2022-01-12 | 2022-03-25 | 中国石油大学(华东) | Petroleum asphalt-based carbon-supported monatomic molybdenum catalyst and preparation method and application method thereof |
| CN114583195B (en) * | 2022-03-17 | 2024-05-14 | 江苏擎动新能源科技有限公司 | Difunctional group modified platinum carbon catalyst and preparation method thereof |
| CN114606516B (en) * | 2022-04-25 | 2023-12-08 | 南昌航空大学 | For electrocatalytic CO 2 Reduced bimetallic monoatomic catalyst and preparation method thereof |
| CN115069270B (en) * | 2022-05-16 | 2023-04-14 | 四川启睿克科技有限公司 | CuSAP/CdS photolysis water hydrogen production catalyst and preparation method thereof |
| CN114870883B (en) * | 2022-06-14 | 2023-08-18 | 南昌航空大学 | Hollow carbon-based Fe monoatomic catalyst and preparation method and application thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101344603A (en) * | 2007-07-13 | 2009-01-14 | 3M创新有限公司 | Method for preparing sulfurated retroreflective sheet and retroreflective product |
| US20160250623A1 (en) * | 2013-10-11 | 2016-09-01 | Nanjing University Of Technology | Catalyst for Benzene Hydroxylation for Preparation of Phenol and Preparation Method Thereof |
| CN108530708A (en) * | 2018-04-27 | 2018-09-14 | 安徽富悦达电子有限公司 | A kind of high-temperature insulation sheath for automobile engine using new energy resources harness |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106450192A (en) * | 2016-10-14 | 2017-02-22 | 浙江天能能源科技股份有限公司 | Silicon/carbon composite material for lithium ion battery and preparation method and application thereof |
| CN109420515B (en) * | 2017-08-21 | 2021-06-22 | 中国科学院大连化学物理研究所 | Preparation method of high-dispersion supported metal catalyst |
| CN110280240A (en) * | 2019-07-10 | 2019-09-27 | 东华理工大学 | A kind of carbon nanosheet supported precious metal nano-particle catalyst and its preparation method and application |
| CN111389437B (en) * | 2020-04-10 | 2021-06-11 | 天津大学 | Molybdenum carbide supported monatomic hydrogenation catalyst, preparation method thereof and application thereof in alkyne semi-hydrogenation |
| CN112371173B (en) * | 2020-11-27 | 2023-09-08 | 沈阳化工研究院有限公司 | Platinum-carbon catalyst applied to hydrogenation of m-nitrobenzenesulfonic acid and preparation method thereof |
-
2021
- 2021-03-10 CN CN202110258913.3A patent/CN112973759B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101344603A (en) * | 2007-07-13 | 2009-01-14 | 3M创新有限公司 | Method for preparing sulfurated retroreflective sheet and retroreflective product |
| US20160250623A1 (en) * | 2013-10-11 | 2016-09-01 | Nanjing University Of Technology | Catalyst for Benzene Hydroxylation for Preparation of Phenol and Preparation Method Thereof |
| CN108530708A (en) * | 2018-04-27 | 2018-09-14 | 安徽富悦达电子有限公司 | A kind of high-temperature insulation sheath for automobile engine using new energy resources harness |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112973759A (en) | 2021-06-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112973759B (en) | Preparation method of metal monatomic catalyst, metal monatomic catalyst and application | |
| CN110252308B (en) | Supported catalyst with active metal dispersed in carrier in atomic level, preparation method and application thereof | |
| CN110170326B (en) | High-dispersion supported noble metal catalytic material and preparation method thereof | |
| CN103030143B (en) | Iron carbide particle, and fabrication method and application thereof | |
| CN108525669B (en) | Highly-dispersed silicon dioxide nanotube supported nickel catalyst and preparation method thereof | |
| CN112044462B (en) | Graphene-loaded transition metal nitride nanocomposite and preparation method and application thereof | |
| CN102451765A (en) | Preparation method for composite oxide carrier | |
| CN111841608B (en) | High-activity and anti-carbon deposition composite catalyst, preparation method thereof and application thereof in methane dry gas reforming | |
| CN110124711B (en) | Preparation method and desulfurization application of few-layer carbon nitride loaded tungsten trioxide nanoparticle catalyst | |
| EP2709755A1 (en) | Method for preparing a supported ruthenium catalyst | |
| CN111266107B (en) | Preparation method and application of resin carbon sphere supported palladium catalyst | |
| CN107308976A (en) | A kind of N doping Carbon Materials load palladium-based catalyst and preparation method and application | |
| CN115109596B (en) | Soil heavy metal stabilizer and preparation method and application thereof | |
| CN115475641B (en) | Metal atom anchored boron-nitrogen co-doped carbon material and preparation method thereof | |
| CN113522331A (en) | Carbon-based cobalt-palladium bimetallic nano catalyst and preparation and application thereof | |
| CN102909034B (en) | Preparation of supported gold-nickel alloy nanocatalyst | |
| CN113663711B (en) | Double-function Cu-based desulfurization catalyst and preparation method and application thereof | |
| Zhang et al. | Steering ammonia decomposition over Ru nanoparticles on ZrO 2 by enhancing metal–support interaction | |
| WO2006006277A1 (en) | Catalyst for cycloolefin production and process for production | |
| CN112569953A (en) | Desulfurization catalyst and preparation method thereof | |
| CN112439421B (en) | Coke oven gas deep desulfurization catalyst and preparation method thereof | |
| CN114768823B (en) | Method for preparing oil product by hydrogenating synthesis gas | |
| CN116060002B (en) | Graphene-loaded metal monoatomic composite material, preparation method and application | |
| CN114471580B (en) | Synthesis and application method of supported nickel-gallium catalyst | |
| CN115999564B (en) | Ni-Mo/SiO for preparing hydrocarbon fuel by catalytic biological grease hydrodeoxygenation2Catalyst |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |