阅读说明：本技术 MoS2负载的单原子“类酶”催化剂及其制备方法与应用 (MoS2Supported monatomic enzyme-like catalyst and preparation method and application thereof ) 是由 娄阳 赵伊 姚庭怡 郭文熠 朱永法 张颖 潘成思 董玉明 于 2020-08-26 设计创作，主要内容包括：本发明公开了一种MoS<Sub>2</Sub>负载的单原子“类酶”催化剂及其制备方法与应用,其制备方法包括：将铂族金属的氯化物或硝酸盐溶于水或醇溶剂中,控制金属前驱体溶液的温度为20～40℃,调节溶液的等电点为3～6,使溶液中的铂族金属形成单分散的构型；将MoS<Sub>2</Sub>载体分散于水或醇溶剂中配制成载体溶液,通过超声振动的方式使所述MoS<Sub>2</Sub>载体均匀分散于载体溶液中；将金属前驱体溶液加入到载体溶液中,使金属前驱体均匀分散于MoS<Sub>2</Sub>载体的表面；经过滤、干燥之后,即得MoS<Sub>2</Sub>负载的单原子“类酶”催化剂。本发明的MoS<Sub>2</Sub>负载的单原子“类酶”催化剂,对巴豆醛催化加氢生成巴豆醇具有高活性和高选择性。(The invention discloses a MoS 2 The preparation method of the loaded monatomic enzyme-like catalyst comprises the following steps: dissolving chloride or nitrate of platinum group metal in water or alcohol solvent, controlling the temperature of metal precursor solution at 20-40 ℃, and adjusting the isoelectric point of the solution to 3-6 to enable the platinum group metal in the solution to form a monodisperse configuration; mixing MoS 2 Dispersing the carrier in water or alcohol solvent to prepare carrier solution, and ultrasonically vibrating the MoS 2 The carrier is uniformly dispersed in the carrier solution; adding the metal precursor solution into the carrier solution to uniformly disperse the metal precursor in the MoS 2 A surface of the support; after being filtered and dried, the MoS is obtained 2 A supported monatomic "enzyme-like" catalyst. MoS of the invention 2 The loaded monatomic enzyme-like catalyst has high activity and high selectivity for crotyl alcohol generated by catalytic hydrogenation of crotonaldehyde.)

1. MoS₂The preparation method of the loaded monatomic enzyme-like catalyst is characterized by comprising the following steps of:

dissolving chloride or nitrate of platinum group metal in water or alcohol solvent to obtain metal precursor solution, controlling the temperature of the metal precursor solution to be 20-40 ℃, and adding acid liquor to adjust the isoelectric point of the solution to be 3-6 so as to enable the platinum group metal in the metal precursor solution to form a monodisperse configuration;

mixing MoS₂Dispersing the carrier in water or alcohol solvent to prepare carrier solution, and ultrasonically vibrating the MoS₂The carrier is uniformly dispersed in the carrier solution; and

adding the metal precursor solution into the carrier solution to uniformly disperse the metal precursor in the MoS₂A surface of the support; filtering and drying to obtain the MoS₂A supported monatomic "enzyme-like" catalyst.

2. A MoS according to claim 1₂The preparation method of the supported monoatomic 'enzyme-like' catalyst is characterized in that the platinum group metal is Pd, Pt, Rh, Ir or Ru.

3. A MoS according to claim 1₂The preparation method of the supported monatomic enzyme-like catalyst is characterized in that the alcohol solvent comprises ethanol and glycol.

4. A MoS according to claim 1₂A method for preparing a supported monatomic enzyme catalyst, characterized in thatThe concentration of the metal precursor solution is 0.05-0.5 mmol/L.

5. A MoS according to claim 1₂The preparation method of the loaded monoatomic enzyme-like catalyst is characterized in that the acid solution is hydrochloric acid.

6. A MoS according to claim 1₂The preparation method of the loaded monatomic enzyme-like catalyst is characterized in that the drying is vacuum drying at 40 ℃ for 12 hours.

7. A MoS according to claim 1₂A method for preparing a supported monatomic enzyme-like catalyst, characterized in that said MoS₂The synthesis method of the carrier comprises the following steps:

mixing ammonium molybdate and thiourea in water, reacting at 180-240 ℃ for 12-24 h, collecting a product after the reaction is finished, washing for multiple times, and drying to obtain the MoS₂And (3) a carrier.

8. A MoS according to claim 1₂The preparation method of the loaded monoatomic enzyme-like catalyst is characterized in that the metal precursor solution is added into the carrier solution at a sample adding rate of 0.5-1.5 ml/min.

9. MoS prepared by the method according to any one of claims 1 to 8₂A supported monatomic "enzyme-like" catalyst.

10. The MoS of claim 9₂Application of a loaded monatomic 'enzyme-like' catalyst in catalyzing crotonaldehyde hydrogenation to generate crotyl alcohol.

Technical Field

The invention relates to the technical field of catalysts, in particular to a MoS₂A loaded monatomic enzyme-like catalyst, a preparation method and application thereof.

Background

The unsaturated enol is used as an important reaction intermediate and has important application in the field of synthesis of fine chemicals such as spices, food additives, medicines, pesticides and the like. The natural sources of such compounds are very limited and are generally prepared from an a, β -unsaturated aldehyde containing a reducing functional group such as a carbonyl group (C ═ O) and a carbon-carbon double bond (C ═ C) by selective hydrogenation of the C ═ O bond. However, the energy barrier for the hydrogenation of C ═ C bonds in unsaturated aldehydes to form low value saturated ketones is more thermodynamically feasible and is 35KJ/mol lower than the energy barrier for the hydrogenation of C ═ O double bonds to form high value unsaturated enols. Therefore, designing and developing a suitable catalyst to realize the selective activation of C ═ O bonds in unsaturated aldehydes to produce unsaturated enols is a very challenging subject in the field of selective hydrogenation, and has great fundamental research significance and industrial application value.

Disclosure of Invention

The invention aims to solve the technical problem of providing MoS with high activity and high selectivity for crotyl alcohol generated by catalytic hydrogenation of crotonaldehyde₂A supported monatomic "enzyme-like" catalyst.

In order to solve the above technical problems, a first aspect of the present invention provides a MoS₂A method for preparing a supported monatomic "enzyme-like" catalyst, comprising the steps of:

dissolving chloride or nitrate of platinum group metal in water or alcohol solvent to obtain metal precursor solution, controlling the temperature of the metal precursor solution to be 20-40 ℃, and adding acid liquor to adjust the isoelectric point of the solution to be 3-6 so as to enable the platinum group metal in the metal precursor solution to form a monodisperse configuration;

mixing MoS₂Dispersing the carrier in water or alcohol solvent to prepare carrier solution, and ultrasonically vibrating the MoS₂The carrier is uniformly dispersed in the carrier solution; and

adding the metal precursor solution into the carrier solution to uniformly disperse the metal precursor in the MoS₂A surface of the support; filtering and drying to obtain the MoS₂A supported monatomic "enzyme-like" catalyst.

According to the invention, the temperature of the precursor solution is controlled to be 20-40 ℃, and the isoelectric point of the solution is adjusted, so that the platinum group metal in the precursor solution forms a monodisperse configuration.

Further, the platinum group metal is Pd, Pt, Rh, Ir, or Ru.

In the present invention, the alcohol solvent may be a commonly used alcohol, preferably ethanol or ethylene glycol.

Further, the concentration of the metal precursor solution is 0.05-0.5 mmol/L.

In the present invention, the isoelectric point of the solution is adjusted by adding an acid solution, which may be a conventional acid solution such as hydrochloric acid.

Further, the drying is preferably carried out at 40 ℃ for 12h under vacuum.

Further, the MoS₂The synthesis method of the carrier comprises the following steps:

mixing ammonium molybdate and thiourea in water, reacting at 180-240 ℃ for 12-24 h, collecting a product after the reaction is finished, washing for multiple times, and drying to obtain the MoS₂And (3) a carrier.

Further, the metal precursor solution is added into the carrier solution at a sample adding rate of 0.5-1.5 ml/min. For the sample adding mode, a peristaltic pump can be adopted for trace sample adding.

A second aspect of the present invention provides the method of the first aspectMoS prepared by the method₂A supported monatomic "enzyme-like" catalyst.

In a third aspect, the present invention provides the MoS of the second aspect₂Application of a loaded monatomic 'enzyme-like' catalyst in catalyzing crotonaldehyde hydrogenation to generate crotyl alcohol.

The invention has the beneficial effects that:

1. the invention is characterized in that the solution temperature, the metal precursor concentration and type, the isoelectric point of the solution, the solvent type and MoS of platinum group metal in the electrostatic adsorption process are adopted₂The optimization and improvement of factors such as the dispersion degree of the carrier and the like realize that the platinum group metal atoms are in MoS₂The atomic scale at the edge of the support disperses to form a unique-O-Mo-O-Pt-O-Mo-O-pocket type active center. The monatomic 'enzyme-like' catalyst has a unique space coordination configuration, shows a space confinement effect similar to that of an enzyme catalyst, and enables the C ═ O bond in a crotonaldehyde molecule to be activated on an active metal site, so that crotyl alcohol can be generated with high selectivity.

2. MoS of the invention₂Supported monatomic "enzyme-like" catalysts, at wide operating temperature window (65 ℃ to 80 ℃), different reactions H₂Under the condition of pressure (2 to 6MPa), the catalyst realizes high activity (> 90%) and high selectivity (94-100%) of the catalyst for hydrogenating the crotonaldehyde into the crotyl alcohol.

Drawings

FIG. 1 is Pt₁/MoS₂The structural schematic diagram of the monatomic enzyme-like catalyst is as follows: (a) atomic resolution electron scanning transmission electron microscopy (HAADF-STEM); (b) a density generalized function theory (DFT) simulation diagram;

FIG. 2 is pure MoS₂，nano-Pt/MoS₂With Pt₁/MoS₂The reaction performance of the monatomic enzyme-like catalyst for catalyzing the selective hydrogenation of the crotonaldehyde to prepare the crotyl alcohol.

Detailed Description

The present invention is further described below in conjunction with the following figures and specific examples so that those skilled in the art may better understand the present invention and practice it, but the examples are not intended to limit the present invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.