Electrode for fuel cell and method for manufacturing same
Provided are an electrode for fuel cell including a support with improved durability and capable of suppressing poisoning of catalyst particles by ionomer, and a method for manufacturing the same. The method at least includes: performing heat treatment of a support made of mesoporous carbon having a crystallite diameter Lc at 002 plane that is 1.5 nm or less, at 1,700° C. or more and less than 2,300° C.; supporting catalyst particles at least inside of the support subjected to the heat treatment; and applying ionomer to the support supporting the catalyst particles for coating.
1. A method for manufacturing an electrode for a fuel cell, comprising:
performing a heat treatment of a support made of a mesoporous carbon having a crystallite diameter Lc at the 002 plane that is 1.5 nm or less, at 1,700° C. or more and less than 2,300° C.;
supporting catalyst particles at least inside of the support subjected to the heat treatment; and
applying an ionomer to the support supporting the catalyst particles for coating,
further comprising, after supporting the catalyst particles and before applying the ionomer for coating, performing an oxidation treatment of at least a surface of the meso-pores of the mesoporous carbon of the support so that an oxygen content per unit area contained in a surface of supported catalyst where the catalyst particles are supported on the support is 0.08 mg/m 2 or more.
2. The method for manufacturing an electrode for a fuel cell according to claim 1 , wherein the heat treatment is performed so that the meso-pores having a size of 2 to 10 nm in the support have a specific surface area of the meso-pores that is 400 m 2 /g or more.
3. The method for manufacturing an electrode for a fuel cell according to claim 1 , wherein, when the supported catalyst subjected to the oxidation treatment is placed under vacuum environment, and when water vapor partial pressure is increased to a vicinity of a saturated water vapor pressure so as to let water vapor adsorbed to the supported catalyst, and when water vapor partial pressure is decreased from a vicinity of the saturated water vapor pressure while letting water vapor adsorbed to the supported catalyst so as to let water vapor adsorbed to the supported catalyst desorb,
let that T1 denotes mass of water vapor adsorbed to the supported catalyst when the water vapor partial pressure is increased to be 60% of the saturated water vapor pressure and T2 denotes mass of water vapor adsorbed to the supported catalyst when the water vapor partial pressure is decreased to be 60% of the saturated water vapor pressure, the oxidation treatment is performed to the supported catalyst so that a relationship of T1/T2≥0.15 is satisfied.
4. The method for manufacturing an electrode for a fuel cell according to claim 1 , wherein, in the oxidation treatment, nitric acid aqueous solution that is 0.1 mol/L or more and is heated to be 60° C. or higher is brought into contact with at least the surface of the meso-pores of the mesoporous carbon for 1 hour or more.