Several concepts for platinum-based catalysts for the oxygen reduction reaction (ORR) are presented that exceed the US Department of Energy targets for Pt-related ORR mass activity. Most concepts achieve their high ORR activity by increasing the Pt specific activity at the expense of a lower electrochemically active surface area (ECSA). In the potential region controlled by kinetics, such a lower ECSA is counterbalanced by the high specific activity. At higher overpotentials, however, which are often applied in real systems, a low ECSA leads to limitations in the reaction rate not by kinetics, but by mass transport. Here we report on self-supported platinum–cobalt oxide networks that combine a high specific activity with a high ECSA. The high ECSA is achieved by a platinum–cobalt oxide bone nanostructure that exhibits unprecedentedly high mass activity for self-supported ORR catalysts. This concept promises a stable fuel-cell operation at high temperature, high current density and low humidification.

提出了一些用于氧还原反应（ORR）的铂基催化剂的概念，这些概念超出了美国能源部关于Pt相关的ORR质量活性的目标。大多数概念通过增加Pt比活度来实现其高ORR活性，但以较低的电化学活性表面积（ECSA）为代价。在动力学控制的潜在区域中，如此低的ECSA被高比活度所抵消。但是，在较高的超电势下（通常在实际系统中使用），低ECSA导致反应速率的限制不是动力学，而是传质。在这里，我们报告了将高比活与高ECSA相结合的自支撑铂-钴氧化物网络。高ECSA是通过铂-钴氧化物骨纳米结构实现的，该结构对自负载ORR催化剂表现出前所未有的高质量活性。这个概念保证了燃料电池在高温，高电流密度和低加湿条件下的稳定运行。