阅读说明：本技术 一种3d多孔钴锡钼三金属催化剂的制备方法 (preparation method of 3D porous cobalt-tin-molybdenum trimetal catalyst ) 是由 侯琳熙 何倩 刘梦颖 黄少唯 安航 于 2019-09-30 设计创作，主要内容包括：本发明属于无机纳米材料制备技术领域,具体涉及一种3D多孔钴锡钼三金属催化剂的制备方法。其是CoSn(OH)<Sub>6</Sub>前驱体与四硫代钼酸铵分散于水中,经过水热、煅烧反应制得所述3D多孔钴锡钼三金属催化剂。该催化剂由二硫化钴、二氧化锡和二硫化钼组成的多孔立方体结构。本发明方法合成简单、成本低、制备的3D多孔钴锡钼三金属化合物将催化活性高的硫化物与导电性良好的氧化物结合,能够发挥化合物间的协同效应,提高各方面的性能。将其作为酸性条件下催化电解水制备氢气的电极材料,具有良好的应用前景。(The invention belongs to the technical field of inorganic nano material preparation, and particularly relates to a preparation method of a 3D porous cobalt-tin-molybdenum trimetal catalyst. Which is CoSn (OH) 6 The precursor and ammonium tetrathiomolybdate are dispersed in water, and the 3D porous cobalt-tin-molybdenum trimetal catalyst is prepared through hydrothermal and calcination reactions. The catalyst is a porous cubic structure consisting of cobalt disulfide, tin dioxide and molybdenum disulfide. The method has simple synthesis and low cost, and the prepared 3D porous cobalt-tin-molybdenum trimetal compound combines the sulfide with high catalytic activity and the oxide with good conductivity, and can exert the functions between the compoundsThe synergistic effect of (1) and the improvement of various performances. The catalyst is used as an electrode material for preparing hydrogen by catalyzing and electrolyzing water under an acidic condition, and has a good application prospect.)

1. the three ~ metal catalyst is characterized by being of a 3D porous structure consisting of cobalt disulfide, tin dioxide and molybdenum disulfide, the particle size of the three ~ metal catalyst is 200 ~ 250 nm, the three ~ metal catalyst is formed by stacking particles inside the three ~ metal catalyst, the particle size of the three ~ metal catalyst is 10 ~ 20 nm, the outside of the three ~ metal catalyst is wound and covered by nanosheets, and the thickness of the nanosheets is 20 ~ 25 nm.

2. the 3D porous cobalt ~ tin ~ molybdenum trimetal catalyst according to claim 1, wherein the 3D porous cobalt ~ tin ~ molybdenum trimetal catalyst has a bimodal pore size distribution, the pore size distribution is 3 ~ 5 nm and 10 ~ 20 nm, and the specific surface area of the 3D porous cobalt ~ tin ~ molybdenum trimetal catalyst is 50 ~ 80 m² g⁻¹。

3. A method of preparing a 3D porous cobalt tin molybdenum trimetallic catalyst according to claim 1, comprising the steps of:

1) Cobalt chloride hexahydrate, tin chloride pentahydrate and dihydrateDissolving sodium citrate in water-alcohol solution with volume ratio of 7:1, adding sodium hydroxide solution dropwise, stirring at room temperature for 0.5h for coprecipitation reaction, centrifuging, washing, and vacuum drying to obtain cubic CoSn (OH)₆A precursor;

2) Mixing the obtained CoSn (OH)₆mixing the precursor and ammonium tetrathiomolybdate according to the mass ratio of 1:0.5 ~ 2, dispersing the mixture in deionized water to enable the concentration of a solute to be 2.5 ~ 5 g/L, carrying out thermal reaction on the mixture for a period of time, centrifuging, washing, and drying in vacuum to obtain a dried product;

3) preserving the heat of the dried product obtained in the step 2) for 2 hours at 350-450 ℃ in a nitrogen atmosphere to obtain the 3D porous cobalt-tin-molybdenum trimetal catalyst.

4. the preparation method of claim 3, wherein the molar ratio of cobalt chloride hexahydrate, tin chloride pentahydrate and sodium citrate dihydrate in step 1) is = 1:0.5 ~ 1.

5. the preparation method according to claim 3, wherein the volume of the sodium hydroxide added in step 1) is 20-30 mL, and the molar concentration is 2 mol/L.

6. the production method according to claim 3, characterized in that: step 2) CoSn (OH)₆the mass ratio of the precursor to the ammonium tetrathiomolybdate is 1:0.5 ~ 2.

7. the preparation method according to claim 3, wherein the temperature of the solvothermal reaction in the step 2) is 160 ℃ and the reaction time is 6-12 h.

8. Use of a 3D porous cobalt tin molybdenum trimetallic catalyst according to claim 1 in the preparation of an electrode material for catalysing hydrogen evolution.

Technical Field

The invention belongs to the technical field of inorganic nano material preparation, and particularly relates to a preparation method of a 3D porous cobalt-tin-molybdenum trimetal catalyst.

background

Hydrogen energy is one of the most promising and clean energy sources to replace fossil fuels because of its high energy density, environmental friendliness and renewability. Wherein, the hydrogen production by water electrolysis is a convenient hydrogen production method, which does not pollute the environment and the obtained hydrogen product has high purity. At present, the best electro-catalyst for catalyzing and electrolyzing water to prepare hydrogen is platinum and platinum-based materials, but the electro-catalyst has high cost, scarce resources and poor durability, and greatly hinders the wide application of the electro-catalyst. Therefore, it is urgent to find a non-noble metal electrocatalyst with high efficiency, low cost and abundant reserves.

As a typical transition metal sulfide material, MoS₂The catalyst is considered to be one of the most promising catalysts in electrocatalytic Hydrogen Evolution (HER) due to the characteristics of low price, high stability, good catalytic performance and the like. Theoretical calculation and experiment prove that MoS₂Mainly present in the MoS alone₂The position of the edges of a small part of the body greatly limits its electrocatalytic activity. Furthermore, MoS₂Conductivity also limits its electrocatalytic properties. Increase of MoS₂The intrinsic activity and the number of active sites of (A) is to increase the MoS₂Two effective ways of electrocatalytic efficiency, namely constructing a heterostructure, is an effective way to improve MoS₂A method of electrocatalytic activity. For example, in the lugguan CN 201910480011.7 patent, which relates to the preparation of a nickel-doped molybdenum disulfide electrocatalyst, the doping of nickel can improve the electrical conductivity of the material, and thus improve its HER catalytic performance. But the heterostructures constructed by this method are limited to the introduction of only highly conductive species. Further, in the cinnarizine, xijimin CN 201810461343.6, CN 201711024065, X patents, heterostructures containing not only a highly conductive composition but also a highly catalytic composition were constructed, but also the present inventors constructed heterostructuresThe synthesized compound is mainly obtained by physical mixing, the synthesis steps are complicated, and an additional sulfur source is needed. Therefore, designing the composition and morphology of the material by a proper synthesis method to increase the number of active sites and the conductivity of the material, thereby effectively improving the performance of the catalyst is a hot spot of current research.

Disclosure of Invention

the invention aims to solve the defects in the prior art, and provides a preparation method of a 3D porous cobalt-tin-molybdenum trimetal catalyst with low cost and good performance, which is simple to synthesize and low in cost, and the prepared 3D porous cobalt-tin-molybdenum trimetal catalyst has excellent HER performance under an acidic condition.

the 3D porous cobalt ~ tin ~ molybdenum trimetal catalyst has a bimodal pore size distribution, the pore size distribution is 3 ~ 5 nm and 10 ~ 20 nm, and the specific surface area of the 3D porous cobalt ~ tin ~ molybdenum trimetal catalyst is 50 ~ 80 m² g⁻¹。

The preparation method comprises the following steps:

1) Dissolving cobalt chloride hexahydrate, tin chloride pentahydrate and sodium citrate dihydrate in a water-alcohol solution with a volume ratio of 7:1, then dropwise adding a sodium hydroxide solution, stirring at room temperature for 0.5h for coprecipitation reaction, centrifuging, washing, and drying in vacuum to obtain cubic CoSn (OH)₆A precursor;

2) Mixing the obtained CoSn (OH)₆mixing the precursor and ammonium tetrathiomolybdate according to the mass ratio of 1:0.5 ~ 2, dispersing the mixture in deionized water to enable the concentration of a solute to be 2.5 ~ 5 g/L, carrying out thermal reaction on the mixture for a period of time, centrifuging, washing, and drying in vacuum to obtain a dried product;

3) preserving the heat of the dried product obtained in the step 2) for 2 hours at 350-450 ℃ in a nitrogen atmosphere to obtain the 3D porous cobalt-tin-molybdenum trimetal catalyst.

in the step 1), the molar ratio of cobalt chloride hexahydrate, tin chloride pentahydrate and sodium citrate dihydrate is = 1:0.5 ~ 1.

the volume of the added sodium hydroxide in the step 1) is 20 ~ 30 mL, and the molar concentration is 2 mol/L.

Step 2) CoSn (OH)₆the mass ratio of the precursor to the ammonium tetrathiomolybdate is 1:0.5 ~ 2.

in the step 2), the temperature of the solvothermal reaction is 160 ℃, and the reaction time is 6 ~ 12 h.

Furthermore, the 3D porous cobalt-tin-molybdenum trimetal catalyst disclosed by the invention is applied to preparation of an electrode material for catalyzing hydrogen evolution, and the 3D porous cobalt-tin-molybdenum trimetal catalyst has excellent performance in preparation of hydrogen by electrolyzing water under an acidic condition.

The invention has the following beneficial effects:

(1) The method has the advantages of wide raw material source, low cost, simple synthesis steps, short experimental period and good repeatability, and is beneficial to wide application.

(2) In the three-metal catalyst of the 3D porous cobalt-tin-molybdenum provided by the invention, high-conductivity SnO₂With highly catalytically active CoS₂and MoS₂The heterostructure of (a) can exert a synergistic effect and increase the conductivity of the compound, and can improve the catalytic efficiency of the compound.

(3) The 3D porous cobalt-tin-molybdenum trimetal catalyst provided by the invention is internally formed by stacking particles, is mainly covered by short nanosheets on the outside, has two specific surface areas with relatively high pore size distribution, and is favorable for the diffusion of electrolyte and gas desorption.

(4) When the 3D porous cobalt-tin-molybdenum trimetal catalyst provided by the invention is tested in an acidic test solution for 8 hours, the current density is basically kept unchanged, and the 3D porous cobalt-tin-molybdenum trimetal catalyst has excellent stability.

Drawings

FIG. 1 shows CoSn (OH) produced under the conditions of example 3₆and SEM images of cobalt tin molybdenum trimetal compounds: wherein (a) and (b) CoSn (OH)₆SEM pictures of (a), (c) and (d) cobalt tin molybdenumSEM image of trimetallic compound.

FIG. 2 is a TEM image of a cobalt tin molybdenum trimetallic compound prepared under the conditions of example 3.

Figure 3 is an XRD profile of the cobalt tin molybdenum trimetallic compound prepared under the conditions of example 3.

FIG. 4 is a nitrogen adsorption-desorption curve of the cobalt-tin-molybdenum trimetal compound prepared under the conditions of example 3

FIG. 5 is a plot of the pore size distribution of the cobalt tin molybdenum trimetallic compound prepared under the conditions of example 3.

FIG. 6 shows that the cobalt-tin-molybdenum trimetal compound prepared under the conditions of Pt/C and example 3 is used as an electrocatalyst at 0.5M H₂SO₄Linear scan polarization curve of (1).

FIG. 7 is a Tafel curve fitted to a polarization curve of a cobalt tin molybdenum oxy trimetal compound prepared under Pt/C and example 3 as an electrocatalyst.

FIG. 8 is a chronoamperometric curve of a cobalt tin molybdenum oxy trimetal compound prepared under the conditions of example 3 as an electrocatalyst at an overpotential of 201 mV.

Detailed Description

For better understanding of the present invention, the present invention will be described in detail below with reference to specific examples, but the present invention is not limited thereto.