A catalyst of high dispersion metal supported by carbon template of molecular sieve, its preparation method and application

Abstract

The application belongs to the field of new energy and new materials, and particularly relates to a catalyst of molecular sieve template carbon loaded with highly dispersed metal and a preparation method and application thereof. The catalyst comprises a metal active component and a carrier, and the carrier is a molecular sieve template carbon with a three-dimensional porous structure; the mass fraction of the metal active component in the catalyst is 0.1-8%. The preparation method comprises the following steps: depositing carbon in a molecular sieve by taking self-made LaY type zeolite as a hard template and ethylene gas as a carbon source; etching in a mixed acid solution to prepare a required zeolite template carbon; impregnating an active metal into the zeolite template carbon by an impregnation method, and reducing in a hydrogen-argon environment to obtain a catalyst of molecular sieve template carbon loaded with metal. The catalyst has a uniform pore structure, a limited domain effect on metal clusters, and is favorable for improving the dispersity of the metal and the stability of the catalyst, and can be applied to an alkaline electrolytic water reaction, and the activity of the catalyst is superior to that of a commercial platinum-carbon catalyst.

Description

Technical Field

[0001] This invention belongs to the field of new energy and new materials, specifically relating to a catalyst with highly dispersed metal supported on a molecular sieve template carbon, its preparation method, and its application. Background Technology

[0002] Developing new energy structures and finding new clean or renewable energy sources are among the important issues we face. Hydrogen energy, as a recognized clean energy source, has attracted considerable attention. Water electrolysis, due to its simple operation and high hydrogen purity, is considered one of the most promising methods for hydrogen production; however, the slow kinetics of water electrolysis hinder the application of fuel cells. Developing highly active, highly stable, and inexpensive electrocatalysts remains a major challenge in the field of hydrogen production through water electrolysis.

[0003] Introducing porous supports with high surface area is a sufficient means to improve the utilization efficiency and stability of metal catalysts through physical constraints. Carbon-based materials are ideal electrocatalyst supports due to their high porosity, excellent electron transfer ability, and tunable morphology. However, preparing carbon materials with uniform porosity and a high degree of graphitization remains a challenge. Notably, using zeolite as a hard template to synthesize carbon materials helps to form a large number of regular and interconnected pore structures (TW200623503A), thereby increasing the three-dimensional (3D) structure of graphene. This method of preparing zeolite-templated carbon materials (ZTCs) effectively compensates for the shortcomings of most other graphitization methods in reducing the porosity and surface area of ​​carbon. However, these materials have not received sufficient attention. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide a catalyst with highly dispersed metal supported on a molecular sieve template carbon, its preparation method, and its application. By using LaY zeolite molecular sieve as a hard template, small molecule carbon is deposited and then acid-etched onto the molecular sieve template to obtain a molecular sieve template carbon with high graphitization, uniform pore size distribution, and large specific surface area. To achieve the above-mentioned objective, the technical solution adopted is as follows:

[0005] A catalyst for highly dispersed metal supported on molecular sieve template carbon, the catalyst comprising a metal active component and a support, wherein the metal active component is one or a mixture of two or more of Pt, Au, Ru, Ir, Pd, Rh, Fe, Ni, Co, Mo, and Mn, and the support is molecular sieve template carbon with a three-dimensional porous structure; the mass fraction of the metal active component in the catalyst is 0.1% to 8%.

[0006] The preparation method of the above-mentioned catalyst with highly dispersed metal supported on a molecular sieve template carbon includes the following steps:

[0007] (1) Preparation of LaY molecular sieve template

[0008] Accurately weigh the alkali source, silicon source, aluminum source, and water according to a certain molar ratio, stir evenly, and let it stand at room temperature for 24 hours to obtain the directing agent; accurately weigh the alkali source, silicon source, aluminum source, and water according to another certain molar ratio, stir evenly, add the above directing agent dropwise, and stir continuously at room temperature to obtain a gel.

[0009] After stirring, the gel was subjected to hydrothermal treatment, and after naturally cooling to room temperature, the solid was filtered and washed with deionized water until the washing solution was neutral. The collected solid precipitate was dried overnight in a 90℃ drying oven. The dried solid was ground into powder and calcined in air at 500℃ for 5 hours to obtain the Y-type molecular sieve template.

[0010] Take 2g of the above molecular sieve, disperse it in 0.1mol / L lanthanum nitrate solution, stir in an 80℃ water bath for 8h, filter and wash, and dry in a 90℃ drying oven overnight to obtain the LaY molecular sieve template;

[0011] (2) Preparation of zeolite template carbon

[0012] Weigh 2g of the LaY molecular sieve obtained in step (1) and deposit carbon in a tube furnace. Heat to 600°C under dry nitrogen gas flow, then switch the gas flow to a mixture of nitrogen, ethylene and steam, and keep at 600°C for a period of time. It is best to switch the gas flow to dry nitrogen gas flow, raise the temperature to 850°C and keep it for 2 hours, and then let it drop naturally to room temperature.

[0013] The resulting reaction product was placed in a mixed acid solution of 0.3 mol / L HF / 0.15 mol / L HCl and stirred in an 80°C water bath for 8 hours. The solid was filtered, washed with a large amount of deionized water until neutral, and dried in a 60°C vacuum oven for 4 hours to obtain zeolite template carbon ZTCs.

[0014] (3) Preparation of catalysts M / ZTCs

[0015] M is the metal active component. Prepare a metal precursor solution containing element M with a concentration of 0.16 mg / mL. Weigh 0.1 g of the product obtained in step (2) and place it in the prepared metal precursor solution. Add it to a beaker together with the stirring magnet. Stir at room temperature for 2 h at 400 r / min. Place it in a 60℃ water bath and stir for 6 h until dry to obtain M / ZTCs.

[0016] (4) Activation of the catalyst

[0017] The reaction product obtained in step (3) is placed in a tube furnace and calcined and reduced for a period of time in a 10 vol% H2 / Ar atmosphere at an appropriate temperature to obtain the final product.

[0018] Preferably, in step (1), when preparing the molecular sieve template directing agent, the molar ratio of the alkali source, silicon source, aluminum source, and water converted to Na2O, SiO2, Al2O3, and H2O is 10-20:10-100:1:100-10000.

[0019] As a further preferred option, when preparing the molecular sieve template directing agent, the molar ratio of the alkali source, silicon source, aluminum source, and water to Na2O, SiO2, Al2O3, and H2O is 10-20:10-30:1:100-500.

[0020] The preparation of the gel mixture involves a molar ratio of alkali source, silicon source, aluminum source, and water (converted to Na2O, SiO2, Al2O3, and H2O) of 0.5-10:10-100:1:100-10000.

[0021] As a further preferred option, the gel mixture is prepared with the molar ratio of alkali source, silicon source, aluminum source, and water (converted to Na2O, SiO2, Al2O3, and H2O) being 0.5-5:10-20:1:100-500.

[0022] Preferably, in step (1), the silicon source used is one or more of tetraethyl silicate, water glass, and sodium silicate; the aluminum source used is one or more of sodium aluminate, aluminum hydroxide, and aluminum nitrate; and the alkali is one or more of potassium hydroxide and sodium hydroxide.

[0023] Preferably, in step (1), when the gel is subjected to hydrothermal treatment, the hydrothermal temperature is 80-120℃ and the hydrothermal time is 12-36h.

[0024] Preferably, in step (2), the ratio of ethylene, nitrogen and steam in the mixed gas flow is 1-4:7-4:0.5-5, and the sample is treated with the above mixed gas flow for 2-4 hours.

[0025] Preferably, in step (4), the catalyst activation and calcination temperature is 0-500℃, the reaction time is 1-3h, and the heating rate is 2-10℃ / min.

[0026] Application of a catalyst with highly dispersed metal supported on a molecular sieve template carbon in alkaline water electrolysis reaction.

[0027] Compared with the prior art, the advantages of the present invention are:

[0028] This invention uses self-made LaY-type zeolite as a hard template and ethylene gas as a carbon source to deposit carbon into a molecular sieve; then it is etched in a mixed acid solution to prepare the desired molecular sieve template carbon.

[0029] This invention is based on the concept of physical pore confinement. Using carbon as a molecular sieve template as a carrier, a solution of metal active components is impregnated into the pores of the molecular sieve template. This preparation method well preserves the three-dimensional continuous porous characteristics of the molecular sieve, has a uniform pore structure, and has a confinement effect on metal clusters. With the assistance of a hydrogen-argon environment, the active components are reduced and confined in situ in the pores of the carbon material through a one-step reduction. The active metal in the prepared catalyst is highly dispersed, with an average particle size of about 2 nm and a uniform size distribution.

[0030] This invention not only provides guidance on the role of highly graphitized three-dimensional porous substrates in promoting water electrolysis, but also offers new insights into the rational design of catalysts with high catalytic activity and stability. Attached Figure Description

[0031] Figure 1 The XRD patterns of LaY and ZTCs provided in Embodiment 1 of the present invention;

[0032] Figure 2 A is the N2 adsorption / desorption isotherm of ZTCs provided in Example 1 of the present invention;

[0033] Figure 2 B is a pore size distribution diagram of ZTCs provided in Embodiment 1 of the present invention;

[0034] Figure 3 The image shows a SEM image of ZTCs provided in Embodiment 1 of the present invention.

[0035] Figure 4 The results of low-magnification TEM images and elemental distribution maps of Ru / ZTCs-300 provided in Example 1, as well as the surface distribution maps of Ru and C elements therein;

[0036] Figure 5 TEM image of the particle size distribution of high-magnification Ru / ZTCs-300 provided in Example 1;

[0037] Figure 6 Alkaline hydrogen evolution LSV polarization curves of Ru / ZTCs-300 and commercial 20% Pt / C provided for Example 1;

[0038] Figure 7 The alkaline hydrogen evolution mass activity curves of Pt / ZTCs-300 and commercial 20% Pt / C provided in Example 3 are shown. Detailed Implementation

[0039] The accompanying drawings are for illustrative purposes only. To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the invention in any way. Unless otherwise specified, the methods, reagents, and equipment used in this invention are all conventional methods, reagents, and equipment in this technical field, and all such reagents and equipment are commercially available.

[0040] Example 1

[0041] (1) Preparation of LaY molecular sieve template

[0042] Sodium hydroxide, aluminum metasilicate, sodium silicate, and water were accurately weighed according to a molar ratio of Na₂O, SiO₂, Al₂O₃, and H₂O of 16:19:1:370, stirred evenly, and aged at room temperature for 24 hours to obtain a directing agent. Sodium hydroxide, aluminum metasilicate, sodium silicate, and water were accurately weighed according to a molar ratio of Na₂O, SiO₂, Al₂O₃, and H₂O of 3:9:1:210, stirred evenly, and the above directing agent was added dropwise while continuously stirring at room temperature to obtain a gel. After stirring, the gel was transferred to a high-temperature reactor and hydrothermally treated at 100°C for 24 hours. After naturally cooling to room temperature, the solid was filtered and washed with deionized water until the washing solution was neutral. The collected solid precipitate was dried overnight in a drying oven at 90°C. The dried solid was ground into powder and calcined at 500°C in air for 5 hours to obtain a Y-type molecular sieve template.

[0043] Take 2g of Y-type molecular sieve, disperse it in 0.1mol / L lanthanum nitrate solution, stir in an 80℃ water bath for 8h, filter and wash, and dry in a 90℃ drying oven overnight to obtain the LaY molecular sieve template.

[0044] (2) Preparation of zeolite template carbon

[0045] 2g of LaY molecular sieve was weighed into a tube furnace and heated to 600℃ under a dry nitrogen stream. The mixture of ethylene / nitrogen and steam was maintained at 600℃ for 1.5h. The gas stream was then switched to a dry nitrogen stream to raise the temperature to 850℃ and maintained for 2h, before naturally cooling to room temperature. The resulting reaction product was placed in a mixed acid solution of 0.3mol / L HF / 0.15mol / L HCl and stirred in an 80℃ water bath for 8h. The solid was filtered, washed with a large amount of deionized water until neutral, and dried in a 60℃ vacuum oven for 4h to obtain zeolite template carbon ZTCs.

[0046] (3) Catalyst preparation

[0047] Weigh 0.1g of the prepared zeolite template carbon and add it to a ruthenium chloride solution, wherein the mass fraction of ruthenium is 5% and the concentration of ruthenium in the solution is 0.16mg / mL. Add the solution to a beaker along with a magnetic stir bar and stir at room temperature for 2 hours at 400r / min. Then place the solution in a 60℃ water bath and stir for 6 hours until dry.

[0048] (4) Activation of the catalyst

[0049] The obtained ruthenium / molecular sieve template carbon precursor was placed in a tube furnace and calcined at 300 °C for 2 h in a 10 vol% H2 / Ar atmosphere to prepare Ru / ZTCs-300.

[0050] The XRD patterns of LaY and ZTCs provided in Example 1 are attached. Figure 1 As shown in the attached figure. The N2 adsorption / desorption isotherms of ZTCs provided in this embodiment are also shown in the attached figure. Figure 2 As shown in Figure A, the aperture distribution diagram is attached. Figure 2 As shown in B, the SEM image is attached. Figure 3 As shown. The low-magnification TEM image and elemental distribution map of ZTCs-300 provided in this embodiment are attached. Figure 4 As shown in the attached high-magnification TEM image, which depicts the particle size distribution. Figure 5 As shown.

[0051] Appendix Figure 1 The strong reflection centered at 2θ = 6.2° indicates that the synthesized zeolite template carbon ZTCs successfully replicated the ordered porous structure of zeolite, forming a periodic structure. Peaks at approximately 25° and 43° indicate the presence of a graphene stacked structure. (Appendix) Figure 2 The BET specific surface area of ​​the ZTCs carrier measured in A was 1549 m². 2 g -1 The cumulative micropore volume is 0.53 cm³. 3 g -1 These figures demonstrate that we have successfully synthesized carbon materials with a large specific surface area. (Appendix) Figure 2 B shows that the zeolite template carbon support includes both micropore and mesopore sizes. (See attached image) Figure 3 This indicates that the synthesized carbon support has a polyhedral morphology.

[0052] Appendix Figure 4 The elemental distribution diagram illustrates the uniform distribution of ruthenium within the carbon support. (See attached diagram.) Figure 5 This also shows that the ruthenium nanoparticles loaded on the ZTCs support are highly dispersed, with an average particle size of about 2 nm.

[0053] Example 2

[0054] (1) Preparation of LaY molecular sieve template

[0055] Sodium hydroxide, aluminum metasilicate, sodium silicate, and water were accurately weighed according to a molar ratio of Na₂O, SiO₂, Al₂O₃, and H₂O of 16:19:1:370, stirred evenly, and aged at room temperature for 24 hours to obtain a directing agent. Sodium hydroxide, aluminum metasilicate, sodium silicate, and water were accurately weighed according to a molar ratio of Na₂O, SiO₂, Al₂O₃, and H₂O of 3:9:1:210, stirred evenly, and the above directing agent was added dropwise while continuously stirring at room temperature to obtain a gel. After stirring, the gel was transferred to a high-temperature reactor and hydrothermally treated at 100°C for 24 hours. After naturally cooling to room temperature, the solid was filtered and washed with deionized water until the washing solution was neutral. The collected solid precipitate was dried overnight in a drying oven at 90°C. The dried solid was ground into powder and calcined at 500°C in air for 5 hours to obtain a Y-type molecular sieve template.

[0056] Take 2g of Y-type molecular sieve, disperse it in 0.1mol / L lanthanum nitrate solution, stir in an 80℃ water bath for 8h, filter and wash, and dry in a 90℃ drying oven overnight to obtain the LaY molecular sieve template.

[0057] (2) Preparation of zeolite template carbon

[0058] 2g of LaY molecular sieve was weighed into a tube furnace and heated to 600℃ under a dry nitrogen stream. The mixture of ethylene / nitrogen and steam was maintained at 600℃ for 1.5h. The gas stream was then switched to a dry nitrogen stream to raise the temperature to 850℃ and maintained for 2h. The temperature was then allowed to drop naturally to room temperature. The resulting reaction product was placed in a mixed acid solution of 0.3mol / L HF / 0.15mol / L HCl and stirred in an 80℃ water bath for 8h. The solid was filtered, washed with a large amount of deionized water until neutral, and dried in a 60℃ vacuum oven for 4h to obtain zeolite template carbon.

[0059] (3) Catalyst preparation

[0060] Weigh 0.1g of the prepared zeolite template carbon and add it to a chloroauric acid solution, wherein the mass fraction of gold is 5% and the gold concentration in the solution is 0.16mg / mL. Add the solution to a beaker along with a magnetic stir bar and stir at room temperature for 2 hours at 400r / min. Then place the solution in a 60℃ water bath and stir for 6 hours until dry.

[0061] (4) Activation of the catalyst

[0062] The obtained gold / molecular sieve template carbon precursor was placed in a tube furnace and calcined at 300°C for 2 hours in a 10 vol% H2 / Ar atmosphere to obtain the final product Au / ZTCs-300.

[0063] Example 3

[0064] (1) Preparation of LaY molecular sieve template

[0065] Sodium hydroxide, aluminum metasilicate, sodium silicate, and water were accurately weighed according to a molar ratio of Na₂O, SiO₂, Al₂O₃, and H₂O of 16:19:1:370, stirred evenly, and aged at room temperature for 24 hours to obtain a directing agent. Sodium hydroxide, aluminum metasilicate, sodium silicate, and water were accurately weighed according to a molar ratio of Na₂O, SiO₂, Al₂O₃, and H₂O of 3:9:1:210, stirred evenly, and the above directing agent was added dropwise while continuously stirring at room temperature to obtain a gel. After stirring, the gel was transferred to a high-temperature reactor and hydrothermally treated at 100°C for 24 hours. After naturally cooling to room temperature, the solid was filtered and washed with deionized water until the washing solution was neutral. The collected solid precipitate was dried overnight in a drying oven at 90°C. The dried solid was ground into powder and calcined at 500°C in air for 5 hours to obtain a Y-type molecular sieve template.

[0066] Take 2g of Y-type molecular sieve, disperse it in 0.1mol / L lanthanum nitrate solution, stir in an 80℃ water bath for 8h, filter and wash, and dry in a 90℃ drying oven overnight to obtain the LaY molecular sieve template.

[0067] (2) Preparation of zeolite template carbon

[0068] 2g of LaY molecular sieve was weighed into a tube furnace and heated to 600℃ under a dry nitrogen stream. A mixture of ethylene / nitrogen and steam at a ratio of 3:5 was used to maintain the temperature at 600℃ for 1.5h. The gas stream was then switched to a dry nitrogen stream to raise the temperature to 850℃ and maintain it for 2h. The temperature was then allowed to drop naturally to room temperature. The resulting reaction product was placed in a mixed acid solution of 0.3mol / L HF / 0.15mol / L HCl and stirred in an 80℃ water bath for 8h. The solid was filtered, washed with a large amount of deionized water until neutral, and dried in a 60℃ vacuum oven for 4h to obtain zeolite template carbon.

[0069] (3) Catalyst preparation

[0070] Weigh 0.1g of the prepared zeolite template carbon and add it to a chloroplatinic acid solution, wherein the mass fraction of platinum is 5% and the platinum concentration in the solution is 0.16mg / mL. Add the solution to a beaker along with a magnetic stir bar and stir at room temperature for 2 hours at 400r / min. Then place the solution in a 60℃ water bath and stir for 6 hours until dry.

[0071] (4) Activation of the catalyst

[0072] The obtained platinum / molecular sieve template carbon precursor was placed in a tube furnace and calcined at 300℃ for 2 hours in a 10 vol% H2 / Ar atmosphere to prepare Pt / ZTCs-300.

[0073] Example 4

[0074] (1) Preparation of LaY molecular sieve template

[0075] Sodium hydroxide, aluminum metasilicate, sodium silicate, and water were accurately weighed according to a molar ratio of Na₂O, SiO₂, Al₂O₃, and H₂O of 16:19:1:370, stirred evenly, and aged at room temperature for 24 hours to obtain a directing agent. Sodium hydroxide, aluminum metasilicate, sodium silicate, and water were accurately weighed according to a molar ratio of Na₂O, SiO₂, Al₂O₃, and H₂O of 3:9:1:210, stirred evenly, and the above directing agent was added dropwise while continuously stirring at room temperature to obtain a gel. After stirring, the gel was transferred to a high-temperature reactor and hydrothermally treated at 100°C for 24 hours. After naturally cooling to room temperature, the solid was filtered and washed with deionized water until the washing solution was neutral. The collected solid precipitate was dried overnight in a drying oven at 90°C. The dried solid was ground into powder and calcined at 500°C in air for 5 hours to obtain a Y-type molecular sieve template.

[0076] Take 2g of Y-type molecular sieve, disperse it in 0.1mol / L lanthanum nitrate solution, stir in an 80℃ water bath for 8h, filter and wash, and dry in a 90℃ drying oven overnight to obtain the LaY molecular sieve template.

[0077] (2) Preparation of zeolite template carbon

[0078] 2g of LaY molecular sieve was weighed into a tube furnace and heated to 600℃ under a dry nitrogen stream. The mixture of ethylene / nitrogen and steam was maintained at 600℃ for 1.5h. The gas stream was then switched to a dry nitrogen stream to raise the temperature to 850℃ and maintained for 2h, before naturally cooling to room temperature. The resulting reaction product was placed in a mixed acid solution of 0.3mol / L HF / 0.15mol / L HCl and stirred in an 80℃ water bath for 8h. The solid was filtered, washed with a large amount of deionized water until neutral, and dried in a 60℃ vacuum oven for 4h to obtain zeolite template carbon.

[0079] (3) Catalyst preparation

[0080] Weigh 0.1g of the prepared zeolite template carbon and add it to the ferric nitrate solution, where the mass fraction of iron is 5% and the iron concentration in the solution is 0.16mg / mL. Add the solution to a beaker along with a magnetic stir bar and stir at room temperature for 2 hours at 400r / min. Then place the solution in a 60℃ water bath and stir for 6 hours until dry.

[0081] (4) Activation of the catalyst

[0082] The obtained iron / molecular sieve template carbon precursor was placed in a tube furnace and calcined at 400℃ for 2 hours in a 10 vol% H2 / Ar atmosphere to obtain the final catalyst Fe / ZTCs-400.

[0083] Example 5

[0084] (1) Preparation of LaY molecular sieve template

[0085] Sodium hydroxide, aluminum metasilicate, sodium silicate, and water were accurately weighed according to a molar ratio of Na₂O, SiO₂, Al₂O₃, and H₂O of 16:19:1:370, stirred evenly, and aged at room temperature for 24 hours to obtain a directing agent. Sodium hydroxide, aluminum metasilicate, sodium silicate, and water were accurately weighed according to a molar ratio of Na₂O, SiO₂, Al₂O₃, and H₂O of 3:9:1:210, stirred evenly, and the above directing agent was added dropwise while continuously stirring at room temperature to obtain a gel. After stirring, the gel was transferred to a high-temperature reactor and hydrothermally treated at 100°C for 24 hours. After naturally cooling to room temperature, the solid was filtered and washed with deionized water until the washing solution was neutral. The collected solid precipitate was dried overnight in a drying oven at 90°C. The dried solid was ground into powder and calcined at 500°C in air for 5 hours to obtain a Y-type molecular sieve template.

[0086] Take 2g of Y-type molecular sieve, disperse it in 0.1mol / L lanthanum nitrate solution, stir in an 80℃ water bath for 8h, filter and wash, and dry in a 90℃ drying oven overnight to obtain the LaY molecular sieve template.

[0087] (2) Preparation of zeolite template carbon

[0088] 2g of LaY molecular sieve was weighed into a tube furnace and heated to 600℃ under a dry nitrogen stream. A mixture of ethylene / nitrogen and steam at a ratio of 3:5 was used to maintain the temperature at 600℃ for 1.5h. The gas stream was then switched to a dry nitrogen stream to raise the temperature to 850℃ and maintain it for 2h. The temperature was then allowed to drop naturally to room temperature. The resulting reaction product was placed in a mixed acid solution of 0.3mol / L HF / 0.15mol / L HCl and stirred in an 80℃ water bath for 8h. The solid was filtered, washed with a large amount of deionized water until neutral, and dried in a 60℃ vacuum oven for 4h to obtain zeolite template carbon.

[0089] (3) Catalyst preparation

[0090] Weigh 0.1g of the prepared zeolite template carbon and add it to a nickel nitrate solution, wherein the mass fraction of nickel is 8% and the ruthenium concentration in the solution is 0.16mg / mL. Add the solution to a beaker along with a magnetic stir bar and stir at room temperature for 2 hours at 400r / min. Then place the solution in a 60℃ water bath and stir for 6 hours until dry.

[0091] (4) Activation of the catalyst

[0092] The obtained nickel / molecular sieve template carbon precursor was placed in a tube furnace and calcined at 300°C for 3 hours in a 10 vol% H2 / Ar atmosphere to obtain Ni / ZTCs-300.

[0093] The electrocatalytic hydrogen evolution activity of the catalyst prepared in Example 1 was tested, and the specific steps are as follows:

[0094] Accurately weigh 5 mg of the catalyst prepared in Example 1 into a 2 mL centrifuge tube, add 0.97 mL of isopropanol and 30 μL of Nafion, and sonicate the mixture for 40 min to form a uniform ink. Drop 5 μL of the ink onto the surface of a glassy carbon electrode, dry at room temperature, and then perform electrochemical tests on a Bio-logic VSP 300 multichannel electrochemical workstation. The glassy carbon electrode modified with the electrocatalyst was used as the working electrode, and graphite rods and Hg / HgO were used as the auxiliary and reference electrodes, respectively. The polarization curve of Ru / TiN-300 was measured in a 1 mol / L KOH solution at a scan rate of 10 mV / s.

[0095] Figure 6 As shown, Ru / ZTCs-300 reaches 10 mAcm -2 The overpotential is only 26mV, which is superior to that of commercial platinum-carbon.

[0096] The Pt / ZTCs-300 catalyst prepared in Example 3 was subjected to the same hydrogen evolution activity test as in Example 1, and the tested polarization curves were converted to mass activity.

[0097] Figure 7 As shown, the mass activity of Pt / ZTCs-300 is also superior to that of commercial platinum-carbon catalysts, demonstrating the universality of this system as a material for hydrogen evolution in water electrolysis.

[0098] The catalysts prepared in other embodiments can also achieve the same effect, so they will not be tested here.

[0099] The applicant declares that the detailed method of the present invention is illustrated by the above embodiments, but the present invention is not limited to the above detailed method, that is, it does not mean that the present invention must rely on the above detailed method to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing a catalyst with a highly dispersed metal supported on a molecular sieve template carbon, characterized in that, The catalyst comprises a metallic active component and a support, wherein the metallic active component is one or a mixture of two or more of Pt, Au, Ru, Ir, Pd, Rh, Fe, Ni, and Co; the support is a molecular sieve template carbon with a three-dimensional porous structure; the mass fraction of the metallic active component in the catalyst is 0.1% to 8%. The preparation method includes the following steps: (1) Preparation of LaY molecular sieve template Accurately weigh the alkali source, silicon source, aluminum source, and water according to a certain molar ratio, stir evenly, and let it stand at room temperature for 24 hours to obtain the directing agent; accurately weigh the alkali source, silicon source, aluminum source, and water according to another certain molar ratio, stir evenly, add the above directing agent dropwise, and stir continuously at room temperature to obtain a gel. In the preparation of molecular sieve template directing agent, the molar ratio of alkali source, silicon source, aluminum source, and water to Na2O, SiO2, Al2O3, and H2O is 10~20:10~30:1:100~500; in the preparation of gel mixture, the molar ratio of alkali source, silicon source, aluminum source, and water to Na2O, SiO2, Al2O3, and H2O is 0.5~5:10~20:1:100~500. After stirring, the gel was subjected to hydrothermal treatment, and after naturally cooling to room temperature, the solid was filtered and washed with deionized water until the washing solution was neutral. The collected solid precipitate was dried overnight in a 90℃ drying oven. The dried solid was ground into powder and calcined in air at 500℃ for 5 hours to obtain the Y-type molecular sieve template. Take 2g of Y-type molecular sieve, disperse it in 0.1mol / L lanthanum nitrate solution, stir in an 80℃ water bath for 8h, filter and wash, and dry in a 90°C drying oven overnight to obtain the LaY molecular sieve template; (2) Preparation of zeolite template carbon Weigh 2g of the LaY molecular sieve obtained in step (1) and deposit carbon in a tube furnace. Heat to 600°C under dry nitrogen gas flow. Then switch the gas flow to a mixture of nitrogen, ethylene and steam. Maintain at 600°C for a period of time. Switch the gas flow to dry nitrogen gas flow and raise the temperature to 850°C and maintain for 2 hours. Then let it cool naturally to room temperature. The resulting reaction product was placed in a mixed acid solution of 0.3 mol / L HF / 0.15 mol / L HCl and stirred in an 80°C water bath for 8 hours. The solid was filtered, washed with a large amount of deionized water until neutral, and dried in a 60°C vacuum oven for 4 hours to obtain zeolite template carbon ZTCs. (3) Preparation of catalysts M / ZTCs M is the active metal component. Prepare a metal precursor solution containing element M with a concentration of 0.16 mg / mL. Weigh 0.1g of the product obtained in step (2) and place it in the prepared metal precursor solution. Add it to a beaker together with the magnetic stir bar. Stir at room temperature for 2 hours at 400 r / min. Place it in a 60℃ water bath and stir for 6 hours until dry to obtain M / ZTCs. (4) Activation of the catalyst The reaction product obtained in step (3) is placed in a tube furnace and calcined and reduced for a period of time in a 10 vol% H2 / Ar atmosphere at an appropriate temperature to obtain the final product.

2. The method for preparing a catalyst with highly dispersed metal supported on a molecular sieve template carbon according to claim 1, characterized in that, In step (1), the silicon source used is one or two of tetraethyl silicate and sodium silicate; the aluminum source used is one or more of sodium aluminate, aluminum hydroxide, and aluminum nitrate; and the alkali is one or two of potassium hydroxide and sodium hydroxide.

3. The method for preparing a catalyst with highly dispersed metal supported on a molecular sieve template carbon according to claim 1, characterized in that, In step (1), when the gel is subjected to hydrothermal treatment, the hydrothermal temperature is 80~120 ℃ and the hydrothermal time is 12~36 h.

4. The method for preparing a catalyst with highly dispersed metal supported on a molecular sieve template carbon according to claim 1, characterized in that, In step (2), the ratio of ethylene, nitrogen and steam in the mixed gas flow is 1~4:7~4:0.5~5, and the sample is treated in the above mixed gas flow for 2~4 hours.

5. The method for preparing a catalyst with highly dispersed metal supported on a molecular sieve template carbon according to claim 1, characterized in that, In step (4), the catalyst activation and calcination temperature is 300~500 ℃, the reaction time is 1~3 h, and the heating rate is 2~10 ℃ / min.

6. A catalyst for highly dispersed metals supported on a molecular sieve template carbon, prepared by any one of claims 1-5.

7. The application of the catalyst with highly dispersed metal supported on a molecular sieve template carbon as described in claim 6 in the alkaline water electrolysis reaction.

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