ABO3 Type High-entropy Perovskite Bax(FeCoNiZrY)0.2O3-delta Electrocatalytic Material and Preparation Method Thereof

Patent metadata

Field	Value
Publication number	US-2023203681-A1
Application number	US-202318176676-A
Country	US
Kind code	A1
Filing date	Mar 1, 2023
Priority date	Sep 26, 2021
Publication date	Jun 29, 2023
Grant date	—

Abstract

The present disclosure discloses an ABO3 type high-entropy perovskite Bax(FeCoNiZrY)0.2O3-δ electrocatalytic material and a preparation method thereof, belonging to the technical field of electrocatalytic materials. The electrocatalytic material is prepared by taking hydrated cobalt nitrate, hydrated ferric nitrate, hydrated nickel nitrate, barium nitrate, hydrated yttrium nitrate, hydrated zirconium nitrate and polyacrylonitrile staple fibers as raw materials through processes of liquid phase chelation, gelation, calcination, etc. The prepared high-entropy perovskite Bax(FeCoNiZrY)0.2O3-δ electrocatalytic material can release more electrochemical active sites due to its special nanostructure, thus showing better electrocatalytic activity. Meanwhile, by adjusting the stoichiometric ratio of A/B-site metals, the electronic structure change of five metals in a catalytic center and the change of an oxygen vacancy content are realized, and the purpose of adjusting and optimizing the nitrogen reduction performance is achieved, so that the electrocatalytic material has excellent electrocatalytic conversion of nitrogen gas into ammonia gas.

First claim

What is claimed is:

1 . An electrocatalyst for ammonia synthesis, wherein the electrocatalyst is an ABO 3 type high-entropy perovskite Ba x (FeCoNiZrY) 0.2 O 3-δ electrocatalytic material, wherein A-site metal of the ABO 3 type is Ba, B-site metals comprise the metals Fe, Co, Ni, Zr and Y, x is 0.9 and 1, and 0<δ<3.

2 . The electrocatalyst for ammonia synthesis according to claim 1 , wherein the atomic ratio of the metals is as follows: Ba:Fe:Co:Ni:Zr:Y=1:0.2:0.2:0.2:0.2:0.2, or Ba:Fe:Co:Ni:Zr:Y=0.9:0.2:0.2:0.2:0.2:0.2.

3 . A method for preparing the electrocatalyst for ammonia synthesis according to claim 1 , wherein the method comprises the following steps:
(1) dissolving polyacrylonitrile powder in N, N-dimethylformamide to obtain a polyacrylonitrile solution, and then carrying out electrospinning; pre-oxidizing a membrane obtained by electrospinning at high temperature, then breaking the pre-oxidized membrane and dispersing the pre-oxidized membrane in water to form a pre-oxidized polyacrylonitrile staple fiber dispersion; (2) dissolving barium salt, ferric salt, cobalt salt, nickel salt, zirconium salt and yttrium salt in water to form an aqueous solution; after that, adding a certain amount of ethylene glycol and citric acid to chelate the metal salts so as to form a clear solution, adjusting the pH to 7-9 with ammonia water, heating and concentrating to form gel and then adding the pre-oxidized polyacrylonitrile staple fiber dispersion obtained in step (1), continuing to concentrate to form gel, and then removing the solvent at high temperature to prepare a precursor powder; and (3) calcining the precursor powder obtained in step (2) to obtain the ABO 3 type high-entropy perovskite Ba x (FeCoNiZrY) 0.2 O 3-δ electrocatalytic material.

4 . The method according to claim 3 , wherein in step (1), the concentration of the polyacrylonitrile solution is 0.08-0.12 g/mL, and the condition of electrospinning is 15-20 kV.

5 . The method according to claim 3 , wherein in step (1), the pre-oxidation temperature is 150-200° C., and the pre-oxidation time is 2-5 hours.

6 . The method according to claim 3 , wherein in step (2), the cobalt salt comprises: Co(NO 3 ) 2 ·6H 2 O, with a concentration of 1.0-1.5 mg/mL; the nickel salt comprises: Ni(NO 3 ) 2 ·6H 2 O, with a concentration of 1.0-1.5 mg/mL; the ferric salt comprises: Fe(NO 3 ) 3 ·9H 2 O, with a concentration of 1.5-2.0 mg/mL; the zirconium salt comprises: Zr(NO 3 ) 4 ·5H 2 O, with a concentration of 1.5-2.0 mg/mL; the yttrium salt comprises: Y(NO 3 ) 3 ·6H 2 O, with a concentration of 1.5-2.0 mg/mL; and the barium salt comprises: Ba(NO 3 ) 2 , when x=0.9, the concentration of the barium salt is 4.0-5.0 mg/mL (excluding 5.0 mg/mL), and when x=1, the concentration of the barium salt is 5.0-5.5 mg/mL.

7 . The method according to claim 3 , wherein the concentration of the citric acid in the aqueous solution of step (2) is 10.0-15.0 mg/mL, and the concentration of the ethylene glycol is 5.0-10.0 mg/mL.

8 . The method according to claim 3 , wherein in step (3), the calcination temperature is 800-1200° C., and the calcination time is 5-10 hours.

9 . A method for preparing ammonia gas, wherein the method comprises employing the electrocatalyst for ammonia synthesis according to claim 1 as an electrocatalyst.

Assignees

• Univ Jiangnan

Inventors

• Liu Tianxi
• Chu Kaibin
• Lai Feili

Classifications

• C01P2004/03

  obtained by SEM · CPC title

• C01P2002/50

  Solid solutions · CPC title

• C25B1/27

  Ammonia · CPC title

• C01P2006/40

  Electric properties · CPC title

• C01P2002/72

  by d-values or two theta-values, e.g. as X-ray diagram · CPC title