Understanding Alkaline Hydrogen Oxidation Reaction on PdNiRuIrRh High‐Entropy‐Alloy by Machine Learning Potential

Abstract

High-entropy alloy (HEA) catalysts have been widely studied in electrocatalysis. However, identifying atomic structure of HEA with complex atomic arrangement is challenging, which seriously hinders the fundamental understanding of catalytic mechanism. Here, we report a HEA-PdNiRuIrRh catalyst with remarkable mass activity of 3.25 mA μg À 1 for alkaline hydrogen oxidation reaction (HOR), which is 8-fold enhancement compared to that of commercial Pt/C. Through machine learning potential-based Monte Carlo simulation, we reveal that the dominant PdÀ PdÀ Ni/PdÀ PdÀ Pd bonding environments and Ni/Ru oxophilic sites on HEA surface are beneficial to the optimized adsorption/desorption of *H and enhanced *OH adsorption, contributing to the excellent HOR activity and stability. This work provides significant insights into atomic structure and catalytic mechanism for HEA and offers novel prospects for developing advanced HOR electrocatalysts.

Non-precious metal high-entropy alloys with d–d electron interactions for efficient and robust hydrogen oxidation reactions in alkaline media

“…Moreover, the Mo 4d and W 5d energy ranges from −7.0 to +6.0 eV, enabling flexible electronic modulations and accelerating site-to-site electron transfer on HEA surfaces. 46 The d-band center, indicative of the binding strength between the metal active center and reactants/intermediates/products, is calculated for various catalysts (Fig. 4b).…”

Recent Advances in Platinum Group Metal Based Alloys for Alkaline Hydrogen Oxidation Reaction

“…Recently, our group synthesized an efficient and stable HEA-NiPdRuIrRh electrocatalyst by using a simple wet-chemical strategy. [62] The HEA-NiPdRuIrRh exhibits excellent alkaline HOR activity and stability, with extraordinary mass activity of 3.25 mA μg À 1 , achieving 52, 26, 12, 7 and 8-folds improvement compared to those of Pd, Ru, Rh, Ir and commercial Pt/C, respectively. The machine learning potential-based Monte Carlo (ML-MC) simulation can be employed in investigating the thermodynamic favorable surfaces of HEAs, though their atomic distribution is complex.…”

High-entropy alloys in electrocatalysis: from fundamentals to applications

“…In a recent study by the Luo group, PdNiRuIrRh HEA NPs were successfully fabricated using a simple wet chemical synthesis method. 275 The selection of Ni in the HEA was based on the fact that Ni-based materials are currently considered the most promising non-noble metal catalysts for the alkaline HOR. Additionally, Pd, Rh, Ru, and Ir were chosen because these PGM catalysts have demonstrated high efficiency for the alkaline HER/HOR, with the alloy formed by these metals and Ni often exhibiting superior catalytic activity compared to the individual metals.…”