Abstract: To find the highly-efficient bifunctional electrocatalyst of oxygen electrode of the PEM unitized regenerative fuel cell (URFC) system，the performance of several bifunctional electrocatalysts for oxygen electrode including both fuel cell and water electrolysis in a single cell PEM URFC system was examined. Among the catalysts in the present study for oxygen electrode，fuel cell performance decreased in the order of Pt black＞Pt/Ru/Ir＞Pt/Ru＞Pt/IrO2～Pt/Ir＞Pt/RuO2，whereas，water electrolysis performance decreased in the order of Pt/IrO2＞Pt/RuO2＞Pt/Ir＞Pt black，showing significant performance improvement by addition of a second metal such as IrO2 to Pt black. Consequently，Pt/IrO2 had the best URFC performance and cycling stability with high round-trip efficiency of the URFC system. Therefore，Pt/IrO2 was a promising oxygen electrode of the PEM URFC system. Calcination temperature had more influence on the performance of URFC in water electrolysis mode than that of URFC in fuel cell mode. Under water electrolysis mode，the performance of electrocatalyst without calcination was higher than that of the calcined electrocatalysts when the current density was more than 600 mA/cm2.

Key words: PEM URFC, bifunctional oxygen electrocatalyst, Pt/IrO2

摘要： 对一体式可再生燃料电池双效氧电极催化剂进行研究，考察了析氧催化剂和贵金属Pt黑组成的复合催化剂的双效性能以及催化剂配比和焙烧温度对性能的影响，用XRD对催化剂的物相特性进行表征。结果表明：复合催化剂的燃料电池性能按以下顺序递减：Pt黑＞Pt/Ru/Ir＞Pt/Ru＞Pt/IrO2～Pt/Ir＞Pt/RuO2；水电解性能按以下顺序递减：Pt/IrO2＞Pt/RuO2＞Pt/Ir＞Pt黑。分析比较，Pt/IrO2复合催化剂表现出良好的燃料电池/水电解双功能特性以及循环稳定性，具有最佳的URFC能量转换效率。因此，Pt/IrO2复合催化剂是最适宜的双效氧电极催化剂。一定温度范围内的焙烧处理对Pt/IrO2催化剂燃料电池性能影响不大，而对水电解性能具有一定的影响，大电流密度运行，未焙烧处理的Pt/IrO2催化剂表现出更好的水电解性能。

关键词: 一体式可再生燃料电池, 双效电催化剂, Pt/IrO2复合催化剂