POLYMER ELECTROLYTE-ELECTRODE ASSEMBLY BODY CATALYST LAYER, POLYMER ELECTROLYTE-ELECTRODE ASSEMBLY BODY, AND FUEL BATTERY USING THEM

To provide a polymer electrolyte-electrode assembly body catalyst layer, capable of performing a high performance catalyst reaction which achieves both of a high proton conductivity and a high gas diffusion property.SOLUTION: A polymer electrolyte-electrode assembly body catalyst layer of the present disclosure, includes: a conductive catalyst carrier material; a catalyst carried by at least the conductive catalyst carrier material; a hydrophilic nature inorganic material of which a mode diameter is smaller than that of the conductive catalyst carrier material; and an ionomer that almost uniformly coats the hydrophilic nature inorganic material. A ratio of an outer front surface area of a part coated with the ionomer in the hydrophilic nature inorganic material and a whole outer surface area of the hydrophilic nature inorganic material is larger than a ratio of an outer surface area of a part coated with the ionomer in the conductive catalyst carrier material and a whole outer surface area of the conductive catalyst carrier material. Thus, an ionomer path with a high continuation is formed as a proton conductive path without blocking a gap as a gas diffusion path, and can provide the polymer electrolyte-electrode assembly body catalyst layer which can perform a catalyst reaction at high efficiency.SELECTED DRAWING: Figure 2 【課題】本開示は、高いプロトン伝導性と高いガス拡散性を両立した高効率な触媒反応を可能とする電解質膜－電極接合体用触媒層を提供する。【解決手段】本開示の電解質膜－電極接合体用触媒層は、導電性触媒担体材料と、少なくとも導電性触媒担体材料に担持された触媒と、導電性触媒担体材料よりもモード径が小さい親水性無機材料と、親水性無機材料を略均一に被覆するアイオノマと、を有する。親水性無機材料におけるアイオノマに被覆される部分の外表面積と親水性無機材料の全外表面積との比が、導電性触媒担体材料におけるアイオノマに被覆される部分の外表面積と導電性触媒担体材料の全外表面積との比よりも大きい。これにより、ガス拡散経路である間隙を閉塞させることなくプロトン伝導経路である連続性の高いアイオノマパスが形成され、高効率な触媒反応を可能とする電解質膜－電極接合体用触媒層を提供することができる。【選択図】図２