Multi‐Sites Electrocatalysis in High‐Entropy Alloys

Abstract

High‐entropy alloys (HEAs) have attracted widespread attention in electrocatalysis due to their unique advantages (adjustable composition, complex surface, high tolerance, etc.). They allow for the formation of new and tailorable active sites in multiple elements adjacent to each other, and the interaction can be tailored by rational selection of element configuration and composition. However, it needs to be further explored in catalyst design, the interaction of elements, and the determination of active sites. This review article focuses on the important progress for multi‐sites electrocatalysis in HEAs. The classification is done on the basis of catalytic reaction, including hydrogen evolution reaction, oxygen evolution reaction, oxygen reduction reaction, alcohol oxidation reaction, carbon dioxide reduction reaction, and nitrogen reduction reaction. Based on experiments and theories, a more in‐depth exploration of the high catalytic activity of HEAs will be conducted, including the selection of elements (the special role of each element in catalysis) and the multi‐sites effect. This review can provide the basis for the element selection and design of HEAs in some reactions, to adjust the compositions of HEAs to improve their intrinsic activity. Furthermore, the remaining challenges and future directions for promising research fields are also provided.

Eight‐Component Nanoporous High‐Entropy Oxides with Low Ru Contents as High‐Performance Bifunctional Catalysts in Zn‐Air Batteries

“…[12][13][14][15][16][17][18][19] These active HEA interfaces consist of numerous atomic combinatorial arrangements, providing a rich local electronic structure potentially superior to the conventional catalysts. [20][21][22][23][24] It is known that noble metals play key roles in many catalytic reactions. [25] For example, Pt is super active for the hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR), and the RuO 2 and IrO 2 are considered as the best catalysts for the electrochemical oxygen evolution reaction (OER).…”

A hollow PdCuMoNiCo high-entropy alloy as an efficient bi-functional electrocatalyst for oxygen reduction and formic acid oxidation

“…14 The inherent synergistic effect among the various element components of HEAs can tune their electronic states, endowing HEAs with possible upgraded catalytic activity. [15][16][17][18] Meanwhile, their high entropy and sluggish diffusion effects greatly enhance their thermal and chemical stability and corrosion resistance, ensuring that HEAs can operate stably under harsh conditions. 19,20 For instance, Huang et al reported that PtRuNiCoFeMo HEA sub-nanometer nanowires (SNWs) with strong interactions between different metal sites exhibited good activity for the alkaline hydrogen oxidation reaction.…”

Active Sites Regulation for High-Performance Oxygen Evolution Reaction Electrocatalysts

“…High-entropy alloy has been considered as the remarkable nonprecious metal-based OER electrocatalysts due to their adjustable composition, complex surface, enhanced wear resistance, etc. ( Li et al, 2021 ; Park et al, 2022 ; Han et al, 2022 ). More importantly, OER is a four-electron/four-proton reaction process and involves the adsorption/desorption of several intermediates (HO*, O*, and HOO*) on the catalyst surface.…”