Non-PGM catalyst for ORR based on pyrolysed poly-complexes

Patent metadata

Field	Value
Publication number	US-9570761-B2
Application number	US-201314435762-A
Country	US
Kind code	B2
Filing date	Oct 15, 2013
Priority date	Oct 15, 2012
Publication date	Feb 14, 2017
Grant date	Feb 14, 2017

Abstract

Novel catalytic materials and novel methods of preparing M-N—C catalytic materials utilizing a sacrificial support approach and using inexpensive active polymers as the carbon and nitrogen source and readily available metal precursors are described.

First claim

What is claimed is:

1. A method for forming a catalytic material comprising:
providing sacrificial template particles;
templating a mixture of reactive polymer precursor and a metal precursor onto the sacrificial template particles under suitable conditions to enable in situ polymerization of the reactive polymer precursors to produce a sacrificial template coated with a reactive polymer containing dispersed catalytic material precursors;
heat treating the mixture after in situ polymerization has initiated; and
removing the sacrificial template particles to produce a highly dispersed, self-supported, high surface area catalytic material.

2. The method of claim 1 wherein the reactive polymer is selected from the group consisting of: melamine, carbaldehyde, carbamide and combinations thereof.

3. The method of claim 2 wherein the metal precursor is iron nitrate.

4. The method of claim 1 wherein the reactive polymer precursor is selected from the group consisting of: melamine (M), formaldehyde (F), urea (U), imidazolidinyl urea (IMDZU), Diazolidinyl urea (DAZU), and pyrrole-2-carboxaldehyde (2-PCA) and combinations thereof.

5. The method of claim 1 wherein the metal precursor is a precursor of iron.

6. The method of claim 5 wherein heat treatment comprises a first pyrolysis conducted at a temperature above 750° C. and below 900° C.

7. The method of claim 1 wherein heat treating the dispersed precursors comprises pyrolysis.

8. The method of claim 1 wherein suitable conditions to enable insitu polymerization comprises the addition of an acid.

9. The method of claim 8 wherein the acid is H 2 SO 4.

10. The method of claim 1 further comprising a second pyrolysis.

11. The method of claim 1 wherein the sacrificial template coated with a reactive polymer containing dispersed electrocatalytic material precursors is ball milled to form a fine powder prior to pyrolysis.

12. An unsupported catalytic material comprising a plurality of highly dispersed active metal sites and a substantial portion of carbon and nitrogen derived from polymer formed from melamine, carbaldehyde, carbamide, formaldyhyde, imidazolidinyl urea, Diazolidinyl urea, pyrrole-2-carboxyaldehyde, or a combination thereof.

13. The unsupported catalytic material of claim 12 wherein the unsupported catalytic material has a surface area of at least 300 m 2 g −1 .

14. The unsupported catalytic material of claim 12 wherein the active metal sites are formed using a metal precursor and the metal precursor is a precursor of iron.

15. The unsupported catalytic material of claim 12 wherein the active metal sites are formed using a metal precursor and the metal precursor is iron nitrate.

16. An unsupported catalytic material comprising a plurality of highly dispersed active metal sites and a substantial portion of carbon and nitrogen derived from polymer formed from melamine, carbaldehyde, carbamide, formaldyhyde, imidazolidinyl urea, Diazolidinyl urea, pyrrole-2-carboxyaldehyde, or a combination thereof formed by:
providing sacrificial template particles;
simultaneously templating a mixture of reactive polymer precursor and a metal precursor onto the sacrificial template particles under suitable conditions to enable in situ polymerization of the reactive polymer precursors to produce a sacrificial template coated with a reactive polymer containing dispersed electrocatalytic material precursors;
heat treating the dispersed precursors; and
removing the sacrificial template particles to produce a highly dispersed, self-supported, high surface area catalytic material.

17. The unsupported catalytic material of claim 16 wherein the sacrificial template coated with a reactive polymer containing dispersed electrocatalytic material precursors is ball milled to form a fine powder prior to heat treatment.

18. The unsupported catalytic material of claim 16 wherein the unsupported catalytic material has a surface area of at least 300 m 2 g −1 .

Assignees

• Serov Alexey
• Atanassov Plamen B
• Halevi Barr
• Short Paul
• Stc Unm

Inventors

• Serov Alexey
• Atanassov Plamen B
• Halevi Barr
• Short Paul

Classifications

• Y02E60/50

  Fuel cells · CPC title

• H01M4/8652

  as mixture · CPC title

• H01M4/8885

  Sintering or firing · CPC title

• H01M4/9008

  Organic or organo-metallic compounds · CPC title

• H01M8/1011

  Direct alcohol fuel cells [DAFC], e.g. direct methanol fuel cells [DMFC] · CPC title