Durable High‐Temperature Proton Exchange Membrane Fuel Cells Enabled by the Working‐Temperature‐Matching Palladium‐Hydrogen Buffer Layer.

The durability degradation during stack‐operating conditions seriously deteriorates the lifetime and performance of the fuel cell. To alleviate the rapid potential rise and performance degradation, an anode design is proposed to match the working temperature of high‐temperature proton exchange membrane fuel cells (HT‐PEMFCs) with the release temperature of hydrogen from palladium. The result is significantly enhanced hydrogen oxidation reaction (HOR) activity of Pd and superior performance of the Pd anode. Furthermore, Pd as hydrogen buffer and oxygen absorbent layer in the anode can provide additional in situ hydrogen and absorb infiltrated oxygen during local fuel starvation to maintain HOR and suppress reverse‐current degradation. Compared with the traditional Pt/C anode, the Pd/C also greatly improved HT‐PEMFCs durability during start‐up/shut‐down and current mutation. The storage/release of hydrogen provides innovative guidance for improving the durability of PEMFCs. [ABSTRACT FROM AUTHOR]