Carbon-based material, electrode catalyst, electrode, gas diffusion electrode, electrochemical device, fuel battery, and process for producing carbon-based material

1. A carbon-based material prepared by doping a base made of graphite or amorphous carbon particles with atoms of metal and non-metal, the non-metal including at least one of nitrogen, boron, sulfur, and phosphorus,

when the metal is not platinum, in a radial distribution function obtained by Fourier transform of a K-edge extended X-ray absorption fine structure (EXAFS) of the metal, a ratio of “A” to “B” being equal to or more than 4.0, wherein “A” denotes an intensity of a highest one of peaks around a distance equal to a coordinate bond length between atoms of the metal and the non-metal and “B” denotes an intensity of a highest one of peaks around a distance equal to a metallic bond length between atoms of the metal, and

when the metal is platinum, in a radial distribution function obtained by Fourier transform of an LIII-edge extended X-ray absorption fine structure (EXAFS) of the platinum, a ratio of “A” to “B” being equal to or more than 4.0, wherein “A” denotes an intensity of a highest one of peaks around a distance equal to a coordinate bond length between atoms of the platinum and the non-metal and “B” denotes an intensity of a highest one of peaks around a distance equal to a metallic bond length between atoms of the platinum.

2. The carbon-based material as set forth in claim 1 , wherein

a molar ratio of atoms of the metal to atoms of carbon determined by XPS is less than 0.01, and

a molar ratio of atoms of the non-metal to atoms of the carbon is less than 0.05.

3. The carbon-based material as set forth in claim 1 , comprising a core layer and a doped layer covering the core layer,

the core layer substantially consisting of the graphite or the amorphous carbon alone, and

the doped layer containing atoms of the non-metal and the metal.

4. The carbon-based material as set forth in claim 1 , wherein

an X-ray diffraction pattern of the carbon-based material shows that a proportion of an intensity of a highest one of peaks derived from an inactive metal compound and a metal crystal to an intensity of a (002) peak is not more than 0.1.

5. The carbon-based material as set forth in claim 1 , wherein

the carbon-based material has a particle shape.

6. The carbon-based material as set forth in claim 1 , wherein:

the non-metal includes nitrogen; and

the metal includes iron.

7. The carbon-based material as set forth in claim 1 , wherein:

the non-metal includes nitrogen; and

the metal includes at least one of cobalt and manganese.

8. An electrode catalyst comprising the carbon-based material as set forth in claim 1 .

9. An electrode comprising the electrode catalyst as set forth in claim 8 .

10. A gas diffusion electrode comprising the electrode catalyst as set forth in claim 8 .

11. An electrochemical device comprising the electrode as set forth in claim 9 .

12. A fuel battery comprising the electrode as set forth in claim 9 .

13. A process for producing the carbon-based material,

the carbon-based material prepared by doping a base made of graphite or amorphous carbon particles with atoms of metal and non-metal, the non-metal including at least one of nitrogen, boron, sulfur, and phosphorus,

when the metal is not platinum, in a radial distribution function obtained by Fourier transform of a K-edge extended X-ray absorption fine structure (EXAFS) of the metal, a ratio of “A” to “B” being equal to or more than 4.0, wherein “A” denotes an intensity of a highest one of peaks around a distance equal to a coordinate bond length between atoms of the metal and the non-metal and “B” denotes an intensity of a highest one of peaks around a distance equal to a metallic bond length between atoms of the metal, and

when the metal is platinum, in a radial distribution function obtained by Fourier transform of an LIII-edge extended X-ray absorption fine structure (EXAFS) of the platinum, a ratio of “A” to “B” being equal to or more than 4.0, wherein “A” denotes an intensity of a highest one of peaks around a distance equal to a coordinate bond length between atoms of the platinum and the non-metal and “B” denotes an intensity of a highest one of peaks around a distance equal to a metallic bond length between atoms of the platinum,

the process comprising steps of:

preparing a mixture of a non-metal containing compound, a metal compound, and a carbon source material, the non-metal containing compound containing non-metal including at least one of nitrogen, boron, sulfur, and phosphorus, and the carbon source material being selected from a group consisting of graphite and amorphous carbon particles; and

heating the mixture to a temperature ranging from 800° C. to 1000° C. for a time of 45 sec or more but less than 600 sec when the carbon source material is graphite; or

heating the mixture at a temperature ranging from 800° C. to 1000° C. for a time of 30 sec or more but less than 300 sec when the carbon source material is the amorphous carbon particles.

14. The process for producing a carbon-based material as set forth in claim 13 , wherein

the non-metal containing compound has a molecular weight of 800 or less.

15. The process for producing a carbon-based material as set forth in claim 13 , wherein

the non-metal containing compound includes at least one compound selected from a group consisting of pentaethylenehexamine, tetraethylenepentamine, triethylenetetramine, and ethylenediamine.

16. An electrochemical device comprising the gas diffusion electrode as set forth in claim 10 .

17. A fuel battery comprising the gas diffusion electrode as set forth in claim 10 .