Multisite Synergism‐Induced Electron Regulation of High‐Entropy Alloy Metallene for Boosting Alkaline Hydrogen Evolution Reaction

Abstract

Designing the high‐entropy alloys (HEAs) electrocatalysts with controllable nanostructures is of great significance for the development of efficient alkaline hydrogen evolution reaction (HER) electrocatalysts. In this study, an ultrathin HEA‐PdPtRhIrCu metallene with abundant lattice distortions and defects is prepared via a facile one‐step hydrothermal method. The synthesized HEA‐PdPtRhIrCu metallene exhibits superior HER performance in a 1 m KOH solution, where the required overpotential of HEA‐PdPtRhIrCu metallene is only 15 mV to reach a current density of −10 mA cm−2 while possessing a low Tafel slope for 37 mV dec−1. Density functional theory calculations further prove that the synergistic effect of the five elements can optimize the electronic structure to enhance the HER activity of the catalysts. In particular, the strong coupling effect and the strong bonding arising from the interaction between the multi‐metal components can facilitate the electron transfer of the surface and high electroactivity. Moreover, the optimized Pt electronic structure in HEA‐PdPtRhIrCu metallene promotes the optimal PtH binding at the Pt site, thus promoting HER performance.

Optimization strategies of high-entropy alloys for electrocatalytic applications

“…Mao et al prepared PdPtRhIrCu HEA with rich lattice distortion and defects by a simple hydrothermal synthesis method. 94 The overpotential of PdPtRhIrCu HEA at 10 mA cm −2 is only 15 mV, which is attributed to the ultra-thin high-entropy structure with lattice distortion and defects, which can provide ultra-high specific surface area, maximum atomic utilization and active surface metal atoms, thus promoting the adsorption and dissociation of reaction intermediates.…”

Electron Regulation of Heterostructured Pt/Rh Metallene Boosts Ethylene Glycol Electrooxidation and Hydrogen Evolution

“…Currently, Pt-based catalysts are one of the most efficient EGOR and HER catalysts. − However, during the EGOR process, Pt is easily deactivated by intermediate products (e.g., CO), leading to the blockage of Pt active sites. − In addition, Rh can promote C–C cleavage at lower potentials and has better-stabilized intermediates, which can serve as a co-element to enhance the electrocatalytic performance of Pt. − Nevertheless, most Rh-based catalysts suffer from relatively low catalytic activity . Optimizing the morphology of catalysts is a useful strategy for improving the catalytic activity.…”

“…24−26 Nevertheless, most Rh-based catalysts suffer from relatively low catalytic activity. 27 Optimizing the morphology of catalysts is a useful strategy for improving the catalytic activity. Recently, metallene, as a new two-dimensional (2D) nanomaterial, has generated great interest in electrocatalytic fields owing to its large surface area, sufficient exposed metal atoms, and unsaturated surface coordination, 28−32 which showed excellent catalytic performance.…”

Enhanced electron penetration triggering interfacial charge redistribution in N-doped graphene-wrapped NiGd nanoparticles for coupling methanol electroreforming to H2 production

“…Electrochemical water splitting can afford high-purity hydrogen gas (H 2 ), which is an important raw material and a sustainable energy carrier. 1–6 The oxygen evolution reaction (OER) takes place at the anode during the water-splitting process, which suffers from sluggish kinetics and consumes ∼90% electrical energy due to the required high overpotential. 7–9 Moreover, the produced O 2 from the OER has little economical value.…”