Effects of Pt loading in the anode on the durability of a membrane–electrode assembly for polymer electrolyte membrane fuel cells during startup/shutdown cycling

• Published in: International journal of hydrogen energy Vol. 37; no. 23; pp. 18455 - 18462
• Main Authors: Eom, KwangSup, Kim, GyeongHee, Cho, EunAe, Jang, Jong Hyun, Kim, Hyoung-Juhn, Yoo, Sung Jong, Kim, Soo-Kil, Hong, Bo Ki
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.12.2012; Elsevier
• Subjects: Alternative fuels. Production and utilization; Anode platinum loading; Applied sciences; Durability; Energy; Exact sciences and technology; Fuels; Hydrogen; Membrane–electrode assembly; Polymer electrolyte membrane fuel cell; Reverse current condition; Startup and shutdown cycling; Reverse current condition; Durability; Polymer electrolyte membrane fuel cell; Membrane–electrode assembly; Anode platinum loading; Startup and shutdown cycling; Anode; Voltage current curve; Polymer electrolytes; Cathode; Hydrogen; Fuel cell vehicles; Dissolution; Discharge charge cycle; Degradation; Corrosion; Platinum; Membrane; Membrane-electrode assembly; Oxidation; Surface area; Performance; Charge transfer; Catalyst; Fuel cell
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2012.09.077

A polymer electrolyte membrane fuel cell (PEMFC) stack of a fuel cell vehicle (FCV) is inevitably exposed to reverse current conditions, which are formed by the oxygen reduction reaction (ORR) induced at the anode with a hydrogen/air boundary during startup/shutdown processes. With an increase in the reverse current, the degradation rate of the cathode that experiences a highly corrosive condition (locally high potential) increases. In this work, the anode Pt loading is decreased from 0.4 to 0.1 mg cm−2 to decrease the reverse current. The decrease in the anode Pt loading is found to decrease the hydrogen oxidation rates (HOR) during normal operation, but this loading decrease barely affected the cell performance. However, a decrease in the anode Pt loading can significantly decrease the reverse current, leading to a diminished cathode degradation rate during startup/shutdown cycling. It is revealed by slow decreases in the cell performance (i–V curves) and electrochemical active surface area (EAS), and a slow increase in the charge-transfer resistance (Rct), which can be attributed to corrosion of the carbon support and dissolution/migration/agglomeration of the platinum catalyst. ► The PEMFC of a FCV is exposed to the reverse current during startup/shutdown cycles. ► A decrease in anode Pt loading from 0.4 to 0.1 mg decreases the reverse current. ► It leads to a diminished cathode degradation rate during startup/shutdown cycles.