Hu Zhiwei, Chen Kuangyin, Zhu Yihua, Liu Bin, Shen Jianhua
Shanghai Engineering Research Centre of Hierarchical Nanomaterials, Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai, 200237, China.
State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing, 100029, China.
Small. 2024 Jun;20(26):e2309819. doi: 10.1002/smll.202309819. Epub 2024 Jan 17.
The unique properties of high entropy alloy (HEA) catalysts, particularly their severe lattice distortion and the synergistic effect of multiple components, endow them with exceptional multifunctional catalytic performance. Herein, it is revealed for the first time, that the ultrasmall PtRhNiFeCu HEA nanoparticles catalyst shows outstanding catalytic activity for both hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR). The catalyst exhibits an impressively low overpotential of 13 mV at 10 mA cm, a Tafel slope of 29.6 mV dec and high mass activity of 7.6 A mg at -50 mV in alkaline media, and long-term stability of at least 20 h. Moreover, the catalyst also demonstrates effective catalytic activity for acidic ORR with a commendable performance of 1.23 A mg , much exceeding the commercial Pt/C catalyst. Density functional theory (DFT) calculations unveil that the efficient electrocatalytic performance for HER and ORR can be primarily attributed to the synergistic effect between components tailors and optimizes the electronic structure of PtRhNiFeCu/C HEA, which not only enhances the HER activity through increasing water capture capability, decreasing energetic barrier for water dissociation, and optimizing hydrogen absorption but also initiates non-platinum active sites with high ORR activity, achieving the improved ORR performance.
高熵合金（HEA）催化剂的独特性能，特别是其严重的晶格畸变和多组分的协同效应，赋予了它们卓越的多功能催化性能。在此首次揭示，超小的PtRhNiFeCu HEA纳米颗粒催化剂对析氢反应（HER）和氧还原反应（ORR）均表现出出色的催化活性。在碱性介质中，该催化剂在10 mA cm时具有低至13 mV的过电位、29.6 mV dec的塔菲尔斜率、在-50 mV时7.6 A mg的高质量活性以及至少20 h的长期稳定性。此外，该催化剂对酸性ORR也表现出有效的催化活性，性能达1.23 A mg，远超商业Pt/C催化剂。密度泛函理论（DFT）计算表明，HER和ORR的高效电催化性能主要归因于各组分之间的协同效应，其调整并优化了PtRhNiFeCu/C HEA的电子结构，这不仅通过提高水捕获能力、降低水分解的能量势垒和优化氢吸附来增强HER活性，还引发了具有高ORR活性的非铂活性位点，从而实现了ORR性能的提升。
