Cathode catalyst layer, manufacturing method thereof and membrane electrode assembly

摘要

According to the present invention, it is possible to improve the use ratio of active sites in a catalyst having oxygen reduction activity so as to provide a cathode catalyst layer and MEA for a fuel cell with high a level of power generation performance. The present invention includes a process of introducing a functional group into a surface of the catalyst 13 which has oxygen reduction activity and a process of blending the catalyst 13 with the functional group on the surface together with an electron conductive material and a proton conductive polymer electrolyte to prepare a catalyst ink for forming the cathode catalyst layer for the fuel cell.

主权项

1. A cathode catalyst layer comprising:
a non-platinum catalyst which contains at least one transition metal selected from the group of Ta, Nb, Ti and Zr and has oxygen reduction activity; an electron conductive material supporting the non-platinum catalyst; and a proton conductive polymer electrolyte, wherein a silane coupling agent having a functional group is chemically bonded to a surface of said non-platinum catalyst, wherein said non-platinum catalyst is partially-oxidized and wherein said functional group is selected from the group of a sulfonate group, a phosphate group and a carboxylic group.