Temperature effects on PEM fuel cells Pt/C catalyst degradation

Operating proton exchange membrane (PEM) fuel cells at relatively high temperatures provides benefits that include greater tolerance to CO, easier management of water, and improved efficiency of heat rejection. At the same time, the degradation of fuel cell components is accelerated at higher cell temperatures, resulting in shortened cell lifetimes. In this study, we investigated temperature effects on cathode Pt/C catalyst durability. Cathode degradation was accelerated using square-wave potential cycling between 0.87 and 1.2 V (vs reference hydrogen electrode). More rapid Pt/C degradation was observed at higher temperatures, resulting in lower performance, loss of Pt catalyst electrochemically active surface area, and deposition of Pt in the membrane. Each has been quantified at 40, 60, and 80 degrees C. More durable catalysts with improved microstructures are needed for commercial applications of fuel cells, and alternative accelerated tests must be developed for catalyst systems operating at higher temperatures. (c) 2007 The Electrochemical Society.