Dynamic SIMS Analysis of PEMFC Catalyst Layer/Solid Electrolyte Interfaces

Abstract

Cobalt polypyrrole-supported carbon (CoPPy/C) has been expected to be a low-cost alternative to platinum catalysts for proton exchange membrane fuel cell (PEMFC) cathode. Although the catalytic activity of the CoPPy/C is relatively high, improvement of the durability to long-term use is still challenging problem. In order to know the deterioration mechanism of PEMFC cathode, dynamic-secondary ion mass spectrometry (D-SIMS) was used in this study for analysis of cathode catalyst layer/solid electrolyte membrane interfaces before and after an aging test. The depth profile of cobalt species across the interface of a CoPPy/C cathode was significantly changed after the aging test. From the depth profile of cobalt in the CoPPy/C catalyst, it is suggested that the cobalt species may transfer in the membrane along with the flow of the back diffusion water.