Crystal-phase engineering that promotes the rearrangement of active atoms to form new structural frameworks achieves excellent result in the field of electrocatalysis and optimizes the performance of various electrochemical reactions. Herein, for the first time, it is found that the different components in metallic aerogels will affect the crystal-phase transformation, especially in high-entropy alloy aerogels (HEAAs), whose crystal-phase transformation during annealing is more difficult than medium-entropy alloy aerogels (MEAAs), but they still show better electrochemical performance. Specifically, PdPtCuCoNi HEAAs with the parent phase of face-centered cubic (FCC) PdCu possess excellent 89.24% of selectivity, 746.82 mmol h⁻¹ g⁻¹_cat. of yield rate, and 90.75% of Faraday efficiency for ethylamine during acetonitrile reduction reaction (ARR); while, maintaining stability under 50 h of long-term testing and ten consecutive electrolysis cycles. The structure–activity relationship indicates that crystal-phase regulation from amorphous state to FCC phase promotes the atomic rearrangement in HEAAs, thereby optimizing the electronic structure and enhancing the adsorption strength of reaction intermediates, improving the catalytic performance. This study provides a new paradigm for developing novel ARR electrocatalysts and also expands the potential of crystal-phase engineering in other application areas.

中文翻译：

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用于增强乙腈电合成乙胺的晶相工程高熵合金气凝胶

促进活性原子重排形成新结构框架的晶相工程在电催化领域取得了优异的成果，优化了各种电化学反应的性能。在此，首次发现金属气凝胶中的不同成分会影响晶相转变，尤其是高熵合金气凝胶（HEAAs），其退火过程中的晶相转变比中熵气凝胶更困难合金气凝胶（MEAA），但它们仍然表现出更好的电化学性能。具体而言，以面心立方（FCC）PdCu为母相的PdPtCuCoNi HEAA具有优异的89.24％选择性，746.82 mmol h ^-1 g ^-1 _cat。乙腈还原反应（ARR）过程中乙胺的产率和法拉第效率为 90.75%；同时，在50小时的长期测试和连续10个电解循环下保持稳定性。构效关系表明，从非晶态到FCC相的晶相调节促进了HEAA中的原子重排，从而优化了电子结构，增强了反应中间体的吸附强度，提高了催化性能。这项研究为开发新型ARR电催化剂提供了新的范例，并扩展了晶相工程在其他应用领域的潜力。