Observation of liquid water behavior on the surface of PEFC catalyst layer by infrared microscopy and performance evaluation

Abstract

In-situ observation of generated liquid water behavior on a catalyst layer of polymer electrolyte fuel cells (PEFCs) during a cell operation with a constant current was conducted by infrared microscopic imaging. Water is generated in the catalyst layer and accumulated water prevents gas transfer. Therefore, to understand liquid water behavior on the catalyst layer and resultant cell performance is an important challenge to design high-performance PEFCs. In this study, a test cell which was constructed from a silicon substrate with a microchannel and a catalyst coated membrane was used. The observation showed a decrease of voltage as an increase of areal water content on the catalyst layer.