Electrocatalysts for the oxygen evolution reaction in acid conditions

Patent metadata

Field	Value
Publication number	US-2025092543-A1
Application number	US-202318469596-A
Country	US
Kind code	A1
Filing date	Sep 19, 2023
Priority date	Sep 19, 2023
Publication date	Mar 20, 2025
Grant date	—

Abstract

An oxygen evolution reduction electrocatalyst includes a pyrochlore compound with the chemical formula Sm2Ru2xM2-2xO7, where M is selected from the group consisting of Ir, Sc, Fe, Cu, Pd, Cr, and Rh, and x is less than 1.0 and greater than or equal to 0.5. Also, a water electrolysis cell includes an anode, a cathode, an electrolyte, and the oxygen evolution reduction electrocatalyst.

First claim

What is claimed is:

1 . An electrocatalyst comprising:
a pyrochlore compound with the chemical formula Sm 2 Ru 2x M 2-2x O 7 where M is selected from the group consisting of Ir, Sc, Fe, Cu, Pd, Cr, and Rh, and x is less than 1.0 and greater than or equal to 0.5.

2 . The electrocatalyst according to claim 1 , wherein M is selected from the group consisting of Sc, Pd, Cr, and Rh.

3 . The electrocatalyst according to claim 2 , wherein M is Cr.

4 . The electrocatalyst according to claim 3 , wherein x is between about 0.5 and about 0.9.

5 . The electrocatalyst according to claim 4 , wherein x is between about 0.6 and about 0.9.

6 . The electrocatalyst according to claim 5 , wherein x is between about 0.7 and about 0.9.

7 . The electrocatalyst according to claim 3 , wherein the pyrochlore compound at a 10.0 mA/cm 2 current density exhibits an overpotential at least 40 millivolts less than Sm 2 Ru 2 O 7 at the 10.0 mA/cm 2 current density.

8 . The electrocatalyst according to claim 7 , wherein the overpotential is at least 50 millivolts less than Sm 2 Ru 2 O 7 at the 10.0 mA/cm 2 current density.

9 . The electrocatalyst according to claim 3 , wherein the pyrochlore compound at an overpotential equal to 1.53 V relative to a reversible hydrogen electrode exhibits a current density at least 25 mA/mg 2 greater than a current density exhibited by Sm 2 Ru 2 O 7 at the overpotential equal to 1.53 V relative to a reversible hydrogen electrode.

10 . The electrocatalyst according to claim 9 , wherein the current density exhibited by the pyrochlore compound is at least 35 mA/mg 2 greater than the current density exhibited by Sm 2 Ru 2 O 7 .

11 . The electrocatalyst according to claim 1 , wherein M is Cr and at a 10.0 mA/cm 2 current density the pyrochlore compound exhibits an overpotential less than an overpotential of the pyrochlore compounds with M being Rh, Sc, Pd, Ir, Cu, or Fe.

12 . The electrocatalyst according to claim 1 , wherein M is Cr and the pyrochlore compound at an overpotential equal to 1.53 V relative to a reversible hydrogen electrode exhibits a current density greater than a current density of the pyrochlore compounds with M being Rh, Sc, Pd, Ir, Cu, or Fe.

13 . An electrocatalyst comprising:
a pyrochlore compound with the chemical formula Sm 2 Ru 2x M 2-2x O 7 , where M is Cr and x is between about 0.5 and about 0.9.

14 . The electrocatalyst according to claim 13 , wherein x is between about 0.6 and about 0.9.

15 . The electrocatalyst according to claim 14 , wherein x is between about 0.7 and about 0.9.

16 . The electrocatalyst according to claim 13 , wherein the pyrochlore compound at a 10.0 mA/cm 2 current density exhibits an overpotential at least 40 millivolts less than Sm 2 Ru 2 O 7 at the 10.0 mA/cm 2 current density.

17 . The electrocatalyst according to claim 16 , wherein the overpotential is at least 50 millivolts less than Sm 2 Ru 2 O 7 at the 10.0 mA/cm 2 current density.

18 . The electrocatalyst according to claim 13 , wherein the pyrochlore compound at an overpotential equal to 1.53 V relative to a reversible hydrogen electrode exhibits a current density at least 35 mA/cm 2 greater than a current density exhibited by Sm 2 Ru 2 O 7 at the overpotential equal to 1.53 V relative to the reversible hydrogen electrode.

19 . A water electrolysis cell comprising:
an anode; a cathode; an electrolyte; and an oxygen evolution reduction electrocatalyst comprising a pyrochlore compound with the chemical formula Sm 2 Ru 2x M 2-2x O 7 , where M is selected from the group consisting of Ir, Sc, Fe, Cu, Pd, Cr, and Rh, and x is less than 1.0 and greater than or equal to 0.5.

20 . The water electrolysis cell according to claim 19 , wherein M is Cr, x is between about 0.5 and about 0.9, and the pyrochlore compound exhibits a 10.0 mA/cm 2 current density for an applied potential that is at least 40 millivolts less than an applied potential for undoped Sm 2 Ru 2 O 7 .

Assignees

• Toyota Eng & Mfg North America
• Toyota Motor Co Ltd

Inventors

• Wang Siwen
• Ling Chen
• Wakabayashi Yui
• Lin Honghong
• Zhou Li Q
• Roberts Charles Alexander
• Jia Hongfei
• Banerjee Debasish

Classifications

• C25B11/04

  characterised by the material · CPC title

• C25B1/04

  by electrolysis of water · CPC title

• C25B11/075 Primary

  consisting of a single catalytic element or catalytic compound · CPC title

• C25B9/17 Primary

  Cells comprising dimensionally-stable non-movable electrodes; Assemblies of constructional parts thereof · CPC title

• Y02E60/36

  Hydrogen production from non-carbon containing sources, e.g. by water electrolysis · CPC title