| abstract |
A catalyst layer that has good long-term water resistance and in which outflow of the hydrophobizing agent present on the catalyst layer surface is prevented, a membrane electrode assembly, a fuel cell, and a method for manufacturing a catalyst layer. The first aspect of the present invention relates to a catalyst layer having a catalyst structural body including platinum and gold, a proton conductive electrolyte, and a siloxane polymer having a hydrophobic group and a group including —SH, wherein a sulfur atom of the group including —SH of the siloxane polymer and the gold of the catalyst structural body are bound by a thiol bond. |