用于碱性水电解的Cr/Cu-MnFeCoNi高熵合金的结构-性能关联
Structure-Property Correlation of Cr/Cu-MnFeCoNi High-Entropy Alloys for Alkaline Water Electrolysis
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中文总结 AI 辅助
该研究对比CrMnFeCoNi与MnFeCoNiCu高熵合金的碱性析氢、析氧性能，发现Cu取代Cr可提升双功能催化活性，其电子结构调控及OER后Cu迁移形成特殊结构的特性，为高效水电解催化剂设计提供了新策略。
中文摘要 AI 辅助
高熵合金（HEAs）凭借其独特的成分复杂性和可调控的表面化学性质，已成为能源转换领域极具潜力的电催化剂。HEA的催化活性通常源于各元素本征活性与界面产生的协同效应之间的相互作用，即使是多组分HEA中的单元素取代，也能显著改变活性表面的表面化学性质和电化学动力学。本文通过对比碱性析氢反应（HER）和析氧反应（OER）的活性，研究了CrMnFeCoNi（HEA-Cr）和MnFeCoNiCu（HEA-Cu）这两种HEA的结构-性能关系。在相同实验条件下，HEA-Cu对HER和OER的性能均优于HEA-Cr，用Cu取代Cr可显著提升双功能活性；与HEA-Cr相比，HEA-Cu的过电位更低（538 mV），塔菲尔斜率更小（165 mV dec⁻¹）。计算分析证实了这些结果，表明Cu取代可调控电子结构，为反应中间体（H*、O*、OH*和OOH*）提供合适的结合能。值得注意的是，与HER不同，OER后回收的HEA-Cu中Cu发生迁移，形成了具有多金属核的富Cu外层壳。这些发现证明，HEA中的单元素取代有望作为设计高性能、高性价比催化剂的策略，用于高效水电解。
英文摘要
High-entropy alloys (HEAs), with their unique compositional-complexity and tunable surface chemistry, have emerged as promising electrocatalysts for energy conversion. The catalytic activity of HEA often arises from the interplay between the intrinsic activity of the individual elements and the synergistic effects generated at the interfaces. Even a single-element substitution in a multicomponent HEA can substantially alter the surface-chemistry and electrochemical kinetics of the active surface. Here we investigated the structure-property relationship of CrMnFeCoNi (HEA-Cr) and MnFeCoNiCu (HEA-Cu) HEAs by comparing the alkaline hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) activity. Under the same experimental condition, HEA-Cu outperforms HEA-Cr towards both HER and OER. Substituting Cr with Cu significantly enhances the bifunctional activity, where HEA-Cu achieved a lower overpotential (538 mV) and Tafel slope (165 mVdec-1) when compared with HEA-Cr. Computational analysis corroborates these findings, showing that Cu substitution modulates the electronic-structure to provide favorable binding energies for reaction intermediates (H*, O*, OH*, and OOH*). Interestingly, unlike HER, recovered HEA-Cu after OER showed migration of Cu forming a Cu-rich outer layer shell with a multimetallic core. These findings demonstrate the potential of single-element substitution in HEAs as a strategy for designing high-performance, cost-effective catalysts for efficient water electrolysis.
