Platinum based high entropy alloy oxygen reduction electrocatalysts for proton exchange membrane fuel cells

As one of the core reactions in proton exchange membrane fuel cell (PEMFC), oxygen reduction reaction (ORR) kinetics is too sluggish to limit the performance of PEMFC. Platinum (Pt) based catalysts for promoting cathodic ORR not only determine the power and service life of fuel cells, but also are strongly associated with the cost. Inspired by the concept of high entropy alloy (HEA), many researchers have developed a series of Pt-based HEAs that can enhance the oxygen reduction activity, thereby increasing the utilization of Pt and reducing costs. In this account, the latest advances on HEA-based catalysts are systematically summarized, with focus on preparation method, material design and electrocatalytic performance. In addition, the challenges in this research field are also put forward, and a series of directions to be explored from the perspectives of component selection, size optimization, morphology control, hierarchical structure, and carrier up-gradation are proosed, which provides a design idea for a new generation of Pt-based HEA catalyst.