High-Entropy Alloy nanocrystal assembled by nanosheets with d-d electron interaction for Hydrogen Evolution Reaction

The development of effective catalysts with superior performance for water splitting into hydrogen is urgent in the catalysis community. Herein, we report unique high entropy alloys (HEAs) – PtMoPdRhNi nanocrystals (NCs) catalysts with strong d-d electron interaction for the first time in the reported HEAs, which encapsulated with radial nanosheets. Through the exploration of the atomic ratio of The development of effective catalysts with superior performance for water splitting into hydrogen is urgent in the catalysis community. Herein, we report unique high entropy alloys (HEAs) – PtMoPdRhNi nanocrystals (NCs) catalysts with strong d-d electron interaction for the first time in the reported HEAs, which encapsulated with radial nanosheets. Through the exploration of the atomic ratio of PtMoPdRhNi, the obtained Pt28Mo6Pd28Rh27Ni15 NCs with the strongest d-d electron interaction display the highest alkaline hydrogen evolution reaction (HER) activity, with the overpotential as low as 9.7 mV at a current density of -10 mA cm-2. The superior HER performance is mainly originated from the d-d electron interaction in consititute metals of HEAs and multi-active sites with optimized energy barriers. In-situ surface enhanced Raman spectroscopy (SERS) and theoretical calculations are combined to reveal the mechanism in both water dissociation and H* adsorption/desorption. This work not only elucidates the complex structural information and catalytic mechanisms of multielement HEA system in depth for further rational design of efficient catalyst, but also highlights HEAs as sufficiently advanced catalysts and accelerates the research of HEAs in energy-related applications.