Twelve-Component Free-Standing Nanoporous High-Entropy Alloys for Multifunctional Electrocatalysis

Nanostructured high-entropy alloys (HEAs) with tunable compositions have attracted intensive scientific attention on their unique structural, catalytic, and energy-storage capabilities. In this work, we introduce a straightforward two-step fabrication procedure to synthesize free-standing single phase multicomponent nanoporous HEAs consisting of 12 or 16 different elements including both noble and non-noble metals. The electrocatalytic results reveal that the synergistic elemental combinations of such HEAs with a fine porous structure give rise to enhanced hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR) catalytic activities superior to the commercial Pt/C and, at the same time, enhanced oxygen evolution reaction (OER) catalytic activity over the commercial IrO₂ catalyst. The demonstrated multifunctional catalytic performance of these free-standing nanoporous HEAs would facilitate large current densities in the water splitting reactions, rechargeable Zn-air batteries, and many other catalytic, sensing, and energy applications.