Electrochimica Acta, Vol.296, 450-457, 2019
Design of Pt-C/Fe-N-S-C cathode dual catalyst layers for proton exchange membrane fuel cells under low humidity
A novel Pt-C/Fe-N-S-C cathode dual catalyst layer (CDCL) is prepared using the method of catalyst sprayed membrane. The membrane electrode assembly (MEA) fabricated from CDCL exhibits excellent water absorption and retention ability, which improves the performance of the corresponding proton exchange membrane fuel cell (PEMFC) at low humidity conditions. Fe-N-S-C catalysts with high Brunauer-Emmett-Teller surface area exhibit a remarkable water vapor sorption capacity. The effects of Fe-N-S-C content, relative humidity, and operating temperature on the performance of MEAs are investigated systematically. It is found that the optimum Fe-N-S-C content is 1.5-2.0 mg cm(-2) and the preferable operating temperature is 70 degrees C. The MEAs with CDCLs show superior performance at 20% relative humidity due to the enhanced water retention ability resulting from the Fe-N-S-C catalysts. At a constant voltage of 0.5 Vat 70 degrees C and 20% relative humidity, the novel self-humidifying MEA shows better durability than the conventional MEA (60% loss after 4 h). (C) 2018 Elsevier Ltd. All rights reserved.
Keywords:Self-humidifying;Cathode dual catalyst layer;Water retention;Low humidity;Non-precious metal catalyst