Catalyst layer forming composition, catalyst layer, membrane electrode assembly, and polymer electrolyte fuel cell

Abstract

To provide a catalyst layer-forming composition, the composition being capable of forming a catalyst layer of a membrane electrode assembly used for a polymer electrolyte fuel cell excellent in power generation performance durability. A catalyst layer-forming composition includes a fluorinated polymer that has a unit having a cyclic ether structure and has an ion exchange group, a catalyst, and a solvent, wherein the fluorinated polymer has an ion exchange capacity of 1.20 meq/g dry resin or less, the catalyst includes a carbon carrier and a metal supported on the carbon carrier, and a ratio of a mass of the fluorinated polymer to a mass of the carbon carrier is 0.6 to 1.5.

Dependencies are inferred from the claim text.