NOBLE METAL CATALYST LAYER, MEMBRANE ELECTRODE ASSEMBLY, ELECTROCHEMICAL CELL AND METHOD FOR PRODUCING NOBLE METAL CATALYST LAYER

摘要

PROBLEM TO BE SOLVED: To provide a noble metal catalyst layer having high catalyst activity and sufficient durability, a membrane electrode assembly, an electrochemical cell and a method for producing the noble metal catalyst layer.SOLUTION: A noble metal catalyst layer includes: a first noble metal porous layer that has a porosity of 65 to 95 vol.% and the proportion of pores having a diameter of 5 to 80 nm accounting for 50% or more; and a second noble metal porous layer that is formed on the first noble metal porous layer and has a porosity of 50 vol.% or less (including 0%) and an average thickness of 3 to 20 nm.