| 摘要 |
PROBLEM TO BE SOLVED: To suppress carbon oxidation of a catalyst layer.SOLUTION: A catalyst ink is used for forming a catalyst layer of a membrane electrode assembly including an electrolyte membrane, a catalyst layer including a catalyst carrying carbon and an ionomer, and a micro porous layer including a carbon and a binder. The catalyst ink includes: a catalyst carrying carbon; a first ionomer including a first molecular weight; a second ionomer having a second molecular weight higher than the first molecular weight; a first solvent having a first solubility parameter; and a second solvent having a second solubility parameter larger than the first solubility parameter. The ratio between the mass of the first solvent and the mass of the second solvent is equal to the ratio between the frequency of peak of the first ionomer and the frequency of peak of the second ionomer in a distribution graph of molecular weights of ionomers. |
