Platinum catalyst degradation in phosphoric acid fuel cells for stationary applications

► PAFC cathode catalyst degradation has been studied after real-world operation. ► Catalyst surface area decay is a function of operation time and temperature. ► The mechanism of catalyst surface area decay is particle migration and coalescence. A study is presented on the degradation of platinum alloy cathode catalysts operated in phosphoric acid fuel cells. The impact of time and temperature on the fundamental decay mechanism was studied with a surface area loss model and experimental electrochemical surface area measurements. It is suggested that platinum particle migration on the carbon support surface is the dominant mechanism for surface area change in these catalysts.