CN-121992427-A - Hollow nano cage hydrogen evolution catalyst with ordered three-dimensional architecture of ultrathin nano sheets rich in metal/oxide interface and preparation method thereof

Abstract

The preparation method comprises the steps of directly preparing metal hydroxide-organic ligand compounds with nanorod morphology through aqueous solution, preparing hollow metal oxysalt hollow nano-cage compounds through secondary hydrothermal, and finally preparing the electrolytic water hydrogen evolution catalyst rich in metal/oxide interfaces through controllable reduction. The electrolytic water hydrogen-separating catalyst prepared by the invention has a nano cage structure formed by vertically and orderly stacking ultrathin nano sheets, and has large specific surface area, high electrocatalytic activity, good stability and high industrial application value.

Inventors

• WEI ZIDONG
• ZHANG LING
• CHEN HONGMEI

Assignees

• 张伶
• 重庆大学

Dates

Publication Date

20260508

Application Date

20241107

Claims (6)

1. 1. A hollow nano cage hydrogen evolution catalyst with ordered three-dimensional structure of ultrathin nano sheets rich in metal/oxide interface and a preparation method thereof are characterized by comprising the following steps of obtaining metal hydroxide-organic ligand compound through hydrothermal preparation of alkaline organic ligand aqueous solution and metal cation solution added with cation stabilizer, then obtaining hollow metal oxysalt hollow nano cage compound through solution phase controllable ion exchange method, and finally obtaining the electrolytic water hydrogen evolution catalyst rich in metal/oxide interface through semi-melting calcination.
2. 2. The method for preparing the electrolytic water hydrogen evolution catalyst according to claim 1, wherein the metal hydroxide-organic ligand compound is prepared by hydrothermal method through an alkaline organic ligand aqueous solution and a metal cation solution added with a cation stabilizer, wherein the cation stabilizer is at least one of ammonium fluoride, sodium salicylate and disodium edetate.
3. 3. A metal hydroxide-organic ligand compound according to any one of claims 1 to 3, wherein the crystal structure of the metal hydroxide-organic ligand compound comprises a layered metal hydroxide layer stabilized with an organic ligand.
4. 4. The method for producing an electrolytic water hydrogen evolution catalyst according to claim 1, wherein the metal in the interface between the metal and the metal oxide is at least one of Pt, ru, ir, pd, ag, au, fe, co, ni, mo, W, cr and Mn, and the metal oxide is at least one of MoO 2 、MoO 3 、Co 2 Mo 3 O 8 、Fe 2 Mo 3 O 8 、Mn 2 Mo 3 O 8 、Zn 2 Mo 3 O 8 、Ni 2 Mo 3 O 8 、Mg 2 Mo 3 O 8 、Cr 2 Mo 3 O 8 、Co 2 MoO 4 、Fe 2 MoO 4 、Mn 2 MoO 4 、Zn 2 MoO 4 、Ni 2 MoO 4 、Mg 2 MoO 4 、Cr 2 MoO 4 、CoMoO 4 、FeMoO 4 、MnMoO 4 、ZnMoO 4 、NiMoO 4 、MgMoO 4 、CrMoO 4 、WO 2 and WO 3 .
5. 5. The solution phase ion exchange method according to claim 1, wherein the solution contains at least one of sodium molybdate, ammonium heptamolybdate, ammonium dimolybdate, sodium tungstate, ammonium tungstate, and carboxamide, cyclohexanetetramine, triazole, and dimethylimidazole.
6. 6. A method for preparing a catalyst according to any one of claims 1 to 3, wherein the semi-melt calcination is performed in a reducing atmosphere at 500 to 900 ℃ for 0.5 to 6 hours, specifically by first calcining in a reducing atmosphere for 0.5 to 3 hours and then calcining in an inert atmosphere for 0 to 2 hours.

Description

Hollow nano cage hydrogen evolution catalyst with ordered three-dimensional architecture of ultrathin nano sheets rich in metal/oxide interface and preparation method thereof 1. Technical field: The invention relates to a hollow nano cage hydrogen evolution catalyst with an ordered three-dimensional framework of ultrathin nano sheets rich in metal/oxide interfaces and a preparation method thereof, in particular to a hydrogen evolution catalyst capable of being prepared in batches. 2. The background technology is as follows: The hydrogen bond energy in the water molecules is up to 498.7kJ/mol, and the speed of hydrogen production by alkaline water electrolysis is limited by the reaction speed of a cathode and an anode. Thus, the development of high performance electrolyzed water hydrogen separation catalysts is extremely important for hydrogen production processes. The traditional electrolyzed water hydrogen evolution catalyst is mainly a noble metal-based electrocatalyst, such as Pt/C, ruO 2, irO 2 and the like, has high activity, but is expensive and has unsatisfactory stability. This results in high cost of hydrogen production by water electrolysis and difficulty in industrialization. Therefore, the development of the non-noble metal-based electrolytic water hydrogen-separating catalyst with high activity and high stability is a key for realizing the industrial application of the electrolytic water hydrogen production technology. Two-dimensional materials have become a research hot spot in recent years due to the uniqueness, for example, two-dimensional ultrathin graphene has good oxygen reduction activity, and two-dimensional ultrathin molybdenum disulfide has excellent hydrogen evolution activity. Due to the problems of easy disordered stacking, easy falling in use, difficult preparation scale and the like, the two-dimensional material mainly made of powder materials at the present stage cannot be directly used for water electrolysis catalysis. However, conventional two-dimensional material catalysts are often prepared using hydrothermal/solvothermal methods. A method for preparing a MoO 3 hydrogen evolution catalyst rich in oxygen vacancies as reported by Steven l. Suib, usa. In addition, the patent No. CN 107335433A discloses a preparation method of a Pt/MoO x hydrogen evolution catalyst. The second widely adopted method is to prepare Mo-based oxide hydrogen evolution catalysts in situ on current collectors by hydrothermal method. For example, CN 115323395A reports a Mo-based oxide self-supporting hydrogen evolution catalyst with strained lattice. Xinliang Feng teaches a method for preparing a hydrogen evolution catalyst rich in NiMo 4/MoO2 interfaces. However, the existing catalyst has the problems that 1) an organic solvent is needed in the preparation process, and serious environmental pollution exists, and 2) the prepared catalyst belongs to a solid structure, has poor water molecule transmission capability and has low electrochemical activity area. The invention provides a method for constructing a molybdenum bronze type oxide ultrathin nanosheet supported by a hollow nano cage structure in situ by using a metal-organic framework compound (MOFs) with larger surface area, adjustable pore structure and monodispersed metal sites as a sacrificial template, so as to realize ordered three-dimensional architecture of a two-dimensional catalyst, fully expose active sites, open fast transmission channels of electrons, electrolyte and bubbles, and realize fast hydrogen evolution under low overpotential. 3. The invention comprises the following steps: In order to solve the defects in the prior art, the technical scheme for solving the technical problems is as follows, and the invention provides a hollow nano cage hydrogen evolution catalyst with an ultrathin nano sheet ordered three-dimensional framework rich in metal/oxide interfaces and a preparation method thereof, wherein the preparation method comprises the following steps: The metal hydroxide-organic ligand compound is prepared by hydrothermal reaction of an alkaline organic ligand aqueous solution and metal cations added with a cation stabilizer, then a hollow metal oxysalt hollow nano cage compound is prepared by a liquid phase controllable ion exchange method, and finally an electrolytic water hydrogen evolution catalyst rich in metal/oxide interfaces is prepared by semi-melting calcination. The cationic stabilizer is at least one of ammonium fluoride, sodium salicylate and disodium ethylenediamine tetraacetate. The organic ligand is at least one of terephthalic acid, trimesic acid and nitrilotriacetic acid. The solute in the secondary hydrothermal reaction is at least one of sodium molybdate, ammonium heptamolybdate, ammonium dimolybdate, ammonium tungstate, sodium tungstate, carbonamide and cyclohexanetetramine. The preparation method has the beneficial effects that 1) water is adopted as a solvent in the preparation process to prepare a catalyst