PtFeCoNiCu high-entropy solid solution alloy as highly efficient electrocatalyst for the oxygen reduction reaction

Searching for an efficient, durable, and low cost catalyst toward oxygen reduc-tion reaction (ORR) is of paramount importance for the application of fuel cell technology. Herein, PtFeCoNiCu high-entropy alloy nanoparticles (PFCNC-HEA) is reported as electrocatalyst toward ORR. It shows remarkable ORR catalytic mass activity of 1.738 A mg(-1) Pt at 0.90 V, which is 15.8 times higher than that of the state-of-art commercial Pt/C catalyst. It also exhibits outstanding stability with negligible voltage decay (3 mV) after 10k cycles accelerated durability test. High ORR activity is ascribed to the ligand effect caused by poly -metallic elements, the optimization of the surface electronic structure, and the formation of multiple active sites on the surface. In the proton exchange mem-brane fuel cell setup, this cell delivers a power density of up to 1.380 W cm(-2) with a cathodic Pt loading of 0.03 mgPt cm(-2), demonstrating a promising catalyst design direction for highly efficient ORR.