Process for producing catalyst for direct-liquid fuel cell, catalyst produced by the process and uses thereof
In a direct-liquid fuel cell supplied directly with a liquid fuel, a process for producing an electrode catalyst for a direct-liquid fuel cell is provided which is capable of suppressing decrease in cathode potential caused by liquid fuel crossover and providing an inexpensive and high-performance electrode catalyst for a direct-liquid fuel cell. The process for producing an electrode catalyst for a direct-liquid fuel cell includes Step A of mixing at least a transition metal-containing compound with a nitrogen-containing organic compound to obtain a catalyst precursor composition, and Step C of heat-treating the catalyst precursor composition at a temperature of from 500 to 1100° C. to obtain an electrode catalyst, wherein part or entirety of the transition metal-containing compound includes, as a transition metal element, at least one transition metal element M1 selected from Group IV and Group V elements of the periodic table.
1. A process for producing an electrode catalyst for a direct-liquid fuel cell comprising:
Step A of mixing at least a transition metal-containing compound with a nitrogen-containing organic compound to obtain a catalyst precursor composition, and
Step C of heat-treating the catalyst precursor composition at a temperature of from 500 to 1100° C. to obtain an electrode catalyst, wherein
part or entirety of the transition metal-containing compound comprises, as a transition metal element, at least one transition metal element M1 selected from Group IV and Group V elements of the periodic table, wherein
the nitrogen-containing organic compound comprises a carbonyl group, wherein
to an α-carbon of the carbonyl group, a nitrogen atom is bonded.
2. The process for producing an electrode catalyst for a direct-liquid fuel cell according to claim 1 , wherein in Step A, the mixing is performed in a solvent.
3. The process for producing an electrode catalyst for a direct-liquid fuel cell according to claim 2 , which comprises, between Step A and Step C, Step B of removing the solvent from the catalyst precursor composition.
4. The process for producing an electrode catalyst for a direct-liquid fuel cell according to claim 2 , wherein at least one of the transition metal-containing compound and the nitrogen-containing organic compound and the solvent comprises oxygen in the molecule.
5. The process for producing an electrode catalyst for a direct-liquid fuel cell according to claim 1 , wherein the transition metal element M1 comprises at least one selected from titanium, zirconium, niobium and tantalum.
6. The process for producing an electrode catalyst for a direct-liquid fuel cell according to claim 1 , wherein in Step A, a solution of the transition metal-containing compound is mixed with a solution of the nitrogen-containing organic compound.
7. The process for producing an electrode catalyst for a direct-liquid fuel cell according to claim 1 , wherein the nitrogen-containing organic compound is a compound capable of forming a chelate together with a transition metal in the transition metal-containing compound.
8. The process for producing an electrode catalyst for a direct-liquid fuel cell according to claim 1 , wherein in Step A, a compound having a diketone structure is further mixed.
9. The process for producing an electrode catalyst for a direct-liquid fuel cell according to claim 1 , wherein the transition metal-containing compound partly comprises, as a transition metal element, at least one transition metal element M2 selected from iron, nickel, chromium, cobalt, vanadium and manganese.
10. The process for producing an electrode catalyst for a direct-liquid fuel cell according to claim 1 , wherein the transition metal-containing compound is at least selected from the group consisting of metal nitrates, metal acid chlorides, metal-containing organic compounds, metal halides, metal perchlorates and metal hypochlorites.
11. The process for producing an electrode catalyst for a direct-liquid fuel cell according to claim 1 , wherein in Step C, the catalyst precursor composition is heat-treated in an atmosphere containing 0.01 to 10 vol % of a hydrogen gas.
12. The process for producing an electrode catalyst for a direct-liquid fuel cell according to claim 1 , wherein Step C is a step in which the catalyst precursor composition is heat-treated at a temperature of from 500 to 1100° C. and the obtained heat-treated product is disintegrated to obtain an electrode catalyst.