High-entropy alloys (HEAs) have emerged as a powerful materials platform for electrocatalysis due to their tunable surface energetics, structural stability, and diverse local atomic environments arising from multielement interactions. Composed of several principal elements in near-equimolar ratios, HEAs leverage high configurational entropy to stabilize single-phase solid solutions, while surface heterogeneity creates new catalytic motifs in which collective electronic and geometric effects yield activities exceeding those of pure metals. These attributes make HEAs particularly promising for the hydrogen evolution reaction (HER).
Platinum-group-metal-containing HEAs (PGM-HEAs) exhibit exceptional HER activity and durability in acidic environments; however, their reliance on multiple precious metals limits large-scale deployment. Recent efforts demonstrate that partial substitution with earth-abundant transition metals can significantly reduce noble-metal content without sacrificing performance. Despite this progress, the atomic-scale origins of HER activity in HEAs—specifically the geometric and electronic descriptors governing optimal hydrogen binding—remain insufficiently understood.
Here, we present an integrated density functional theory (DFT) and machine learning (ML) framework for discovering PGM-lean HEAs optimized for HER. Equimolar binary and ternary alloys are constructed from a nine-metal design space (Pt, Pd, Ir, Rh, Fe, Co, Ni, Mo, W), yielding 120 unique compositions. Representative surface configurations are selected using Kennard–Stone sampling and modeled as close-packed FCC(111) and BCC(110) slabs. Hydrogen adsorption energetics, and local active-site descriptors are computed using DFT and analyzed using ML models to establish structure–property relationships.
Benchmark calculations on elemental FCC(111) surfaces reproduce expected periodic trends, with hydrogen adsorption free energies ranging from −0.46 eV on Ni(111) to −0.24 eV on Pt(111) at 1/4 monolayer coverage, consistent with d-band theory. Coverage effects are quantified by comparing 2×2×7 and 3×3×7 slab models, revealing stabilization of H* by approximately 0.02 eV at lower coverage. These results validate the computational methodology and establish a robust foundation for screening multicomponent HEA surfaces. The combined DFT–ML framework enables the rational identification of cost-effective, high-performance HEA electrocatalysts while providing fundamental insight into active-site chemistry in complex alloy systems. All computational data will be made available upon request to promote transparency and reproducibility.
A Hierarchical Site to Composition Machine Learning (HS2C‐ML) framework to accelerate the discovery of efficient HEA catalysts for alkaline hydrogen evolution reaction (HER) using high‐entropy alloys.
Shiyu Zhen, Lingwei Wang, Jinhao Wang et al.· Advanced Functional Material...· 0 citations
The sluggish kinetics of the ammonia oxidation reaction constitute a critical bottleneck in the development of low‐temperature direct ammonia fuel cells. High‐entropy alloys (HEAs), owing to their diverse active sites, have emerged as promising catalysts. However, their vast compositional space makes traditional quantum chemical screening prohibitively expensive. In this study, we provide a computational proof of concept showing that the classical
d
‐band center theory fails to predict the ammonia oxidation activity of quinary HEAs and exhibits a negligible correlation with the energy barrier of the rate‐determining step. To address this limitation, we employed the Sure Independence Screening and Sparsifying Operator (SISSO) method to construct a transparent and interpretable symbolic descriptor, achieving excellent predictive accuracy (
R
2
= 0.981) within the range of the training data. This descriptor extends beyond simple single‐electron parameters by integrating the synergistic effects of electron‐donating ability, lattice stiffness, and local electronegativity perturbations. This data‐driven approach reduces computational costs by several orders of magnitude relative to exhaustive density functional theory (DFT) screening and identifies an “isolated‐surrounded” geometric configuration as a highly active site that significantly enhances intrinsic catalytic activity from a thermodynamic perspective. Crucially, the predicted motif should be interpreted within the hydrazine‐mediated thermodynamic framework used here, and its thermodynamic superiority may shift if alternative kinetic pathways dominate under operating conditions. This structural motif promotes efficient NN coupling while suppressing site poisoning. Overall, this study provides a coordination chemistry‐based blueprint for the rational design of next‐generation catalysts with reduced platinum‐group‐metal content and offers a theoretical framework for future experimental validation.
Shangfeng Jiang, Ting Tao, Kexiang Guo et al.· ENERGY & ENVIRONMENTAL M...· 0 citations
Ru‐based solid‐solution alloys have emerged as attractive substitutes for Pt‐based electrocatalysts in the alkaline hydrogen evolution reaction (HER). However, the vast compositional space of these alloys hinders rapid catalyst discovery. Existing machine‐learning design strategies are largely based on idealized simulation data, limiting their experimental relevance and screening efficiency. Herein, we develop an interpretable machine‐learning framework informed by experiment to facilitate the rapid screening of Ru‐based HER electrocatalysts. Built on an experimental dataset, the framework integrates electronic descriptors, interpretability analysis, a Bayesian‐optimized surrogate model and uncertainty‐aware ranking to efficiently identify promising compositions. Interpretability analysis identifies V, Co, and Ru as the key elements governing catalytic performance, whereas the surrogate model maps HER activity across the ternary alloy space to define a confined high‐performance composition window. Guided by this framework, the optimized V
17
Co
31
Ru
52
catalyst exhibits an overpotential of 61.7 mV at a current density of 100 mA·cm
−2
in 1 M KOH, while maintaining stable operation for 260 h under the same current density. This work provides a rapid, interpretable and experimentally relevant strategy for discovering high‐performance alkaline HER electrocatalysts.
Jing Yang, Jun Yu, Jianming Cai et al.· Materials Genome Engineering...· 0 citations
High-entropy oxides (HEOs), which contain multiple cations with diverse valence states and highly disordered local environments, offer a much broader compositional and active-site space than conventional single-component oxides. This diversity creates opportunities for tailoring catalytic properties, but it also makes rational design considerably more difficult. The formation and stability of HEOs phases depend on the combined effects of configurational entropy, mixing enthalpy, oxidation potential, valence compatibility, and synthesis conditions. Meanwhile, their catalytic behavior is often controlled by oxygen vacancies, surface segregation, in situ reconstruction, and dynamically evolving active sites under operating conditions. Artificial intelligence (AI) provides a promising means of managing this complexity by learning relationships among composition, structure, defects, adsorption behavior, and catalytic performance. This review summarizes the major challenges in HEOs catalyst design, discusses data representation and model selection, and examines AI applications in phase stability prediction, hydrogen production, oxygen evolution, thermal catalysis, photocatalysis, and electrocatalyst discovery. It further emphasizes the need to move beyond single-property prediction toward multi-objective optimization and closed-loop integration of AI, DFT, MLIP-based sampling, operando characterization, and experimental validation.
Ying He, Hai-Yang Cheng, Tong Zhou et al.· Advances in Materials· 0 citations
Hydrogen is central to the global clean energy transition, yet the widespread use of green hydrogen is constrained by its dependence on costly, supply-limited platinum-based catalysts in Proton Exchange Membrane (PEM) electrolyzers. While alternatives have been explored, identifying efficient and stable non-platinum catalysts remains a major challenge due to the vast chemical space and the expense of experimental screening. This study pioneers a novel unsupervised machine learning framework to systematically map this vast chemical space and identify promising catalyst candidates without reliance on pre-existing experimental data. Using the tmQM dataset comprising over 108 000 transition metal–ligand complexes; we selected five key descriptors (HOMO–LUMO gap, dipole moment, molecular size, metal node degree, and total charge) to represent catalytic potential and stability. Three unsupervised clustering algorithms (K-Means, DBSCAN, and Gaussian Mixture Models) were applied to identify chemically and electronically distinct groups. Unlike supervised models that predict properties for known structures, our unsupervised approach uncovers previously unidentified classes of non-platinum complexes that possess features ideal for catalytic activity. This work establishes a new, efficient workflow for catalyst science, shifting the focus from slow, one-by-one candidate evaluation to a rapid, holistic mapping of chemical space to pinpoint the most promising regions for focused experimental investigation. Importantly, all shortlisted complexes are structurally documented in crystallographic databases, which enables direct experimental validation and minimizes trial-and-error in material design.
Achouak Benarbia, Ali S. Alshami, Ayyaz Mustafa et al.· RSC Advances· 0 citations
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