Design of Pt-C/Fe-N-S-C cathode dual catalyst layers for proton exchange membrane fuel cells under low humidity. (10th February 2019) - Yin, Yan
Abstract: 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 °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 V at 70 °C and 20% relative humidity, the novel self-humidifying MEA shows better durability than the conventional MEA (60% loss after 4 h). Highlights: A self-humidifying MEA is fabricated with Pt-C/Fe-N-S-C cathode dual catalyst layer. The novel MEA exhibits excellent water retention ability under 20% relative humidity. The high BET surface area of microporous Fe-N-S-C catalyst promotes water storage. The MEA exhibits stable performance for about 60 h at 20% relative humidity.