Catalyst-carrier carbon material, solid-polymer fuel cell catalyst, solid-polymer fuel cell, and method for manufacturing catalyst-carrier carbon material
A carbon material for catalyst carrier use excellent in both durability and power generation performance under operating conditions at the time of low humidity, in particular both durability of a carbon material for catalyst carrier use with respect to repeated load fluctuations due to startup and shutdown and power generation performance under operating conditions at the time of low humidity, and a catalyst for solid-polymer fuel cell use prepared using the same etc. are provided. To solve this technical problem, according to one aspect of the present invention, there is provided a carbon material for catalyst carrier use satisfying the following (A) to (D): (A) an oxygen content O ICP of 0.1 to 3.0 mass % contained in the carbon material for catalyst carrier use; (B) a residual amount of oxygen O 1200° C. of 0.1 to 1.5 mass % remaining after heat treatment in an inert gas (or vacuum) atmosphere at 1200° C.; (C) a BET specific surface area of 300 to 1500 m 2 /g; and (D) a G-band half-width ΔG of 30 to 70 cm −1 detected in a range of 1550 to 1650 cm −1 of the Raman spectrum.
1. A carbon material for catalyst carrier use able to carry a catalyst for solid-polymer fuel cell use, said carbon material for catalyst carrier use satisfying the following (A) to (D):
(A) an oxygen content O ICP of 0.1 to 3.0 mass % contained in the carbon material for catalyst carrier use;
(B) a residual amount of oxygen O 1200° C. of 0.1 to 1.5 mass % wherein the residual amount of oxygen is measured by heating the carbon material in an inert gas (or vacuum) atmosphere at 1200° C.;
(C) a BET specific surface area of 300 to 1500 m 2 /g; and
(D) a G-band half-width ΔG of 30 to 70 cm −1 detected in a range of 1550 to 1650 cm −1 of the Raman spectrum.
2. The carbon material for catalyst carrier use according to claim 1 , wherein the residual amount of oxygen O 1200° C. is 0.1 to 1.2 mass %.
3. The carbon material for catalyst carrier use according to claim 1 or 2 , wherein a residual amount of hydrogen H 1200° C. at the time of treatment in an inert gas (or vacuum) atmosphere at 1200° C. is 0.005 to 0.080 mass %, wherein the residual amount of hydrogen is measured by heating the carbon material.
4. The carbon material for catalyst carrier use according to claim 1 or 2 , wherein the oxygen content O ICP is 0.1 to 2.0 mass %.
5. The carbon material for catalyst carrier use according to claim 1 or 2 , wherein the BET specific surface area is 500 to 1500 m 2 /g.
6. The carbon material for catalyst carrier use according to claim 1 or 2 , further satisfying the following (E) to (H):
(E) a CO gas quantity Q CO of 50 to 250 μmol/g generated at 600 to 900° C. in temperature region in TPD measurement;
(F) a CO 2 gas quantity Q CO2 of 10 to 100 μmol/g generated at 300 to 700° C. in temperature region in TPD measurement;
(G) a micropore area S micro of 200 to 800 m 2 /g; and
(H) Q CO >Q CO2 .
7. The carbon material for catalyst carrier use according to claim 6 , wherein said CO gas quantity Q CO is 80 to 200 μmol/g.
8. The carbon material for catalyst carrier use according to claim 6 , wherein said CO 2 gas quantity Q CO2 is 15 to 60 μmol/g.
9. The carbon material for catalyst carrier use according to claim 7 , wherein said CO 2 gas quantity Q CO2 is 15 to 60 μmol/g.
10. The carbon material for catalyst carrier use according to claim 1 or 2 , further satisfying the following (I) to (J):
(I) a nitrogen content N ICP of 0.3 to 5.0 mass % contained in the carbon material for catalyst carrier use; and
(J) a residual amount of nitrogen N 900° C. of 0.2 to 4.0 mass % wherein the residual amount of nitrogen is measured by heating the carbon material in an inert gas (or vacuum) atmosphere at 900° C.
11. The carbon material for catalyst carrier use according to claim 10 , wherein the BET specific surface area is 400 to 1200 m 2 /g.
12. The carbon material for catalyst carrier use according to claim 10 , wherein a G-band half-width ΔG detected in a range of 1550 to 1650 cm −1 of the Raman spectrum is 30 to 60 cm −1 .
13. The carbon material for catalyst carrier use according to claim 11 , wherein a G-band half-width ΔG detected in a range of 1550 to 1650 cm −1 of the Raman spectrum is 30 to 60 cm −1 .
14. The carbon material for catalyst carrier use according to claim 10 , wherein in an N 1s spectrum measured by XPS, an N 1s intensity ratio (N-Q/N-6) of an N-6 peak with a binding energy near 398.5 eV and an N-Q peak near 400.5 eV is 0.2 to 1.6 in range.
15. The carbon material for catalyst carrier use according to claim 10 , wherein a residual amount of nitrogen N 900° C. is 0.2 to 3.5 mass %.
16. The carbon material for catalyst carrier use according to claim 1 or 2 , further satisfying the following (K):
(K) a boron content B ICP of 0.3 to 5.0 mass %.
17. The carbon material for catalyst carrier use according to claim 16 , wherein the oxygen content O ICP is 0.3 to 3.0 mass %.
18. The carbon material for catalyst carrier use according to claim 16 , wherein the BET specific surface area S BET is 300 to 1000 m 2 /g.
19. The carbon material for catalyst carrier use according to claim 17 , wherein the BET specific surface area S BET is 300 to 1000 m 2 /g.
20. The carbon material for catalyst carrier use according to claim 16 , wherein in a B 1s spectrum measured by XPS, an intensity ratio (BO/BC) of a peak (BO) corresponding to a B—O bond with a binding energy near 192 eV and a peak (BC) corresponding to a B—C bond with a binding energy near 186 eV is 0.2 to 1.5.
21. The carbon material for catalyst carrier use according to claim 16 , wherein the residual amount of oxygen O 900° C. after heat treatment in an inert gas atmosphere at 900° C. is 0.2 to 2.0 mass %, wherein the residual amount of oxygen is measured by heating the carbon material.
22. A catalyst for solid-polymer fuel cell use comprising the carbon material for catalyst carrier use according to claim 1 or 2 and a catalyst metal carried in said carbon material for catalyst carrier use.
23. The catalyst for solid-polymer fuel cell use according to claim 19 , wherein said catalyst metal is platinum or a platinum alloy mainly comprised of platinum.
24. A solid-polymer fuel cell comprising the catalyst for solid-polymer fuel cell use according to claim 22 .
25. A solid-polymer fuel cell comprising the catalyst for solid-polymer fuel cell use according to claim 23 .
26. A method of production of a carbon material for catalyst carrier use according to claim 10 ,
said method comprising:
an oxidation treatment step of oxidizing a porous carbon material to introduce oxygen-containing functional groups into said porous carbon material;
a step of adjusting the residual amount of oxygen O 1200° C. by subsequent heat treatment in an inert atmosphere;
a nitrogen substitution step of substituting nitrogen-containing functional groups for part or all of said oxygen-containing functional groups by nitrogen substitution treatment of heating the porous carbon material obtained by adjusting the residual amount of oxygen O 1200° C. , in an ammonia gas atmosphere; and
a functional group modifying step of heat treating the porous carbon material after nitrogen substitution treatment obtained at said nitrogen substitution step, in an inert gas and/or ammonia gas atmosphere to modify the nitrogen-containing functional groups formed in the nitrogen substitution step to nitrogen-containing functional groups mainly comprised of pyridine-type nitrogen and quaternary-type nitrogen.
27. The method of production of a carbon material for catalyst carrier use according to claim 10 ,
said method comprising:
an oxidation treatment step of oxidizing a porous carbon material to introduce oxygen-containing functional groups into said porous carbon material;
a step of adjusting the residual amount of oxygen O 1200° C. by subsequent heat treatment in an inert atmosphere;
a carrying treatment step of making the porous carbon material obtained in the step of adjusting said residual amount of oxygen O 1200° C. carry a nitrogen-containing organic compound; and
a fixation treatment step of heat treating the porous carbon material after the carrying treatment obtained by this carrying treatment step in an inert gas and/or reducing gas atmosphere at 500 to 1100° C. to fix the nitrogen in the nitrogen-containing organic compound on the porous carbon material.
28. The method of production of a carbon material for catalyst carrier use according to claim 27 , wherein said carrying treatment step comprising dispersing the porous carbon material in a nitrogen-containing organic compound solution obtained by dissolving the nitrogen-containing organic compound in a solvent, then evaporating off the solvent from the obtained nitrogen-containing organic compound solution.
29. The method of production of a carbon material for catalyst carrier use according to claim 27 , wherein said fixation treatment step comprising performing heat treatment in a reducing gas atmosphere containing 5 to 100 vol % of ammonia gas as a reducing gas and having a balance of an inert gas, at 500 to 1100° C.
30. The method of production of a carbon material for catalyst carrier use according to claim 28 , wherein said fixation treatment step comprising performing heat treatment in a reducing gas atmosphere containing 5 to 100 vol % of ammonia gas as a reducing gas and having a balance of an inert gas, at 500 to 1100° C.
31. The method of production of a carbon material for catalyst carrier use according to claim 27 , wherein said fixation treatment step comprising performing heat treatment in a reducing gas atmosphere containing 5 to 100 vol % of ammonia gas as a reducing gas and having a balance of an inert gas, at 500 to 1100° C., then performing heat treatment again in an inert gas atmosphere at 700 to 1100° C.
32. The method of production of a carbon material for catalyst carrier use according to claim 27 , wherein said porous carbon material is a porous carbon material controlled in crystallinity obtained by heat treating the porous carbon material in an inert gas atmosphere at 1400 to 2500° C. to control the crystallinity.
33. The method of production of a carbon material for catalyst carrier use according to claim 27 , wherein a BET specific surface area of said porous carbon material is 300 to 1200 m 2 /g.
34. The method of production of a carbon material for catalyst carrier use according to claim 27 , wherein a melting point, decomposition temperature, or sublimation temperature of said nitrogen-containing organic compound is 200° C. or more.
35. The method of production of a carbon material for catalyst carrier use according to claim 16 ,
said method comprising:
an oxidation treatment step of oxidizing the porous carbon material to introduce oxygen-containing functional groups into said porous carbon material;
a step of adjusting the residual amount of oxygen O 1200° C. by subsequent heat treatment in an inert atmosphere;
a boron source carrying step of making a starting carbon material comprised of a porous carbon material obtained in said step of adjusting the residual amount of oxygen O 1200° C. carry a boron source comprised of a boron-containing compound,
a boron introducing step of heat treating the boron source-carrying carbon material obtained at said boron source carrying step in an inert gas atmosphere to make boron diffuse to the inside of the carbon material; and
an oxygen content adjusting step of oxidizing the boron-containing carbon material obtained in said boron introducing step in an oxidizing gas atmosphere, then heat treating the boron-containing carbon material in an inert gas and/or reducing gas atmosphere to adjust the oxygen content.