Applications and developments of high-entropy alloys toward electrocatalytic oxygen reduction reaction
The development of highly efficient catalysts for oxygen reduction reaction(ORR)is the key to improve the performance of fuel cells and metal-air batteries.However,ORR is a kinetic slow reaction with high overpotential,which limits the energy conversion efficiency of fuel cells and metal-air batteries.High-entropy alloy is a new kind of alloy,which is consisted of five or more metal ele-ments with(nearly)equimolar ratios.With unique composition and structural advantages,high-entro-py alloy can effectively accelerate ORR kinetics and lower overpotential,showing remarkable catalytic performance toward ORR.In this paper,the structures,properties,preparation methods and applications of high entropy alloys in catalytic ORR were reviewed,and the challenges and development perspec-tives were proposed.