Bi-functional catalysts for oxygen reduction and oxygen evolution

Patent metadata

Field	Value
Publication number	US-9647275-B2
Application number	US-201314407997-A
Country	US
Kind code	B2
Filing date	Mar 15, 2013
Priority date	Jun 13, 2012
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

A porous metal-oxide composite particle suitable for use as a oxygen reduction reaction or oxygen evolution reaction catalyst and sacrificial support based methods for making the same.

First claim

What is claimed is:

1. A method for forming a porous metal oxide material comprising:
providing a solution comprising a plurality of dispersed sacrificial template particles;
reacting one or more metal oxide precursors onto the dispersed sacrificial template particles to produce coated template particles;
pyrolyzing and calcining the coated template particles; and
removing the sacrificial template particles to produce a highly dispersed, self-supported, high surface area electrocatalytic material.

2. The method of claim 1 wherein the metal in the metal oxide is a transition metal.

3. The method of claim 1 wherein at least one of the metal oxide precursors is a metal citrate or metal nitrate.

4. The method of claim 1 wherein the step of reacting one or more metal oxide precursors onto the sacrificial template particles comprises mixing a colloidal suspension of template particles with a solution containing a transition metal citrate or nitrate and sodium nitrate.

5. The method of claim 4 wherein the step of heat treating the coated template particles further comprises calcination.

6. The method of claim 4 wherein the colloidal suspension comprises sucrose and urea.

7. The method of claim 1 wherein the step of removing the sacrificial template particles comprises chemical etching.

8. The method of claim 1 wherein the chemical etchant is HF.

9. The method of claim 1 wherein the metal oxide precursor is selected from the group consisting of cobalt nitrate, zirconium oxynitrate hydrate, indium chloride tetrahydrate, venadyl sulfate hydrate, praseodymium nitrate hexahydrate, tin chloride pentahydrate, cerium nitrate hexahydrate, iron nitrate nonhydrate, yttrium nitrate hexahydrate, ammonium tungstate, niobium chloride, antimony chloride, neodymium nitrate hexahydrate, nickel nitrate hexahydrate and tantalum ethoxide.

10. The method of claim 2 wherein the transition metal is selected from the group consisting of Ce, Cr, Cu, Fe, Mo, Ni, Ru, Ta, Ti, V, W, and Zr.

11. The method of claim 4 wherein the colloidal suspension comprises a pore forming agent.

12. The method of claim 1 wherein the sacrificial template particles are non-porous.

13. The method of claim 12 wherein the sacrificial template particles are fumed silica.

14. A method for forming a porous metal oxide material comprising:
providing a solution comprising a plurality of dispersed sacrificial template particles;
reacting one or more metal oxide precursors onto the dispersed sacrificial template particles by mixing a colloidal suspension of template particles with a solution containing a transition metal citrate or nitrate and sodium nitrate to produce coated template particles;
heat treating the coated template particles; and
removing the sacrificial template particles to produce a highly dispersed, self-supported, high surface area electrocatalytic material.

15. The method of claim 14 wherein the step of heat treating the coated template particles comprises pyrolyzation and calcination.

16. The method of claim 14 wherein the colloidal suspension comprises sucrose and urea.

17. The method of claim 14 wherein the metal in the metal oxide is a transition metal.

18. The method of claim 17 wherein the transition metal is selected from the group consisting of Ce, Cr, Cu, Fe, Mo, Ni, Ru, Ta, Ti, V, W, and Zr.

19. The method of claim 14 wherein the colloidal suspension comprises a pore forming agent.

20. The method of claim 14 wherein the sacrificial template particles are non-porous.

Assignees

• Serov Alexey
• Andersen Nalin
• Atanassov Plamen B
• Stc Unm

Inventors

• Serov Alexey
• Andersen Nalin
• Atanassov Plamen B

Classifications

• C01G51/04

  Oxides · CPC title

• B01J23/18

  Arsenic, antimony or bismuth · CPC title

• B01J23/14

  of germanium, tin or lead · CPC title

• B01J37/06

  Washing {(B01J37/0009, B01J37/0018 take precedence)} · CPC title

• B01J23/75

  Cobalt · CPC title