Zhang Lingjie, Cai Weiwei, Bao Ningzhong, Yang Hui
State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, P. R. China.
State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing, Jiangsu, 210009, P. R. China.
Adv Mater. 2022 Jul;34(26):e2110511. doi: 10.1002/adma.202110511. Epub 2022 May 22.
High-entropy (HE) electrocatalysts are becoming a research hotspot due to their interesting "cocktail effect" and have great potential for tailored catalytic properties. However, it is still a great challenge to illustrate their inherent catalytic mechanism for the "cocktail effect", and there is also a paucity of quantitative descriptors to characterize the specific catalytic activity and give logical design strategies for HE systems. Herein, the unexpected activation of all metal sites in HE Cu-Co-Fe-Ag-Mo (oxy)hydroxides for the oxygen evolution reaction (OER) is reported, and it is found that metal-oxygen d-p hybridization, as an effective descriptor, can indicate the intrinsic activity of each metal site. According to the quantitative hybridization, introducing an electron donor (e.g., Ag) is raised and verified to reinforce the electrocatalytic activity of the HE system. Consequently, Ag-decorated Co-Cu-Fe-Ag-Mo (oxy)hydroxide (Ag@CoCuFeAgMoOOH) electrocatalysts are constructed by an electrochemical reconstruction method, and their OER performances are thoroughly characterized. The Ag@CoCuFeAgMoOOH is verified with a low overpotential (270 mV at 100 mA cm ) and a small Tafel slope (35.3 mV dec ), as well as good electrochemical stability. The favorable activity of the electron donor and underlying synergistic "cocktail effect" are demonstrated and disclosed. This work opens up a new strategy to guide the design/fabrication of advanced HE electrocatalysts.
高熵（HE）电催化剂因其有趣的“鸡尾酒效应”正成为研究热点，并且在定制催化性能方面具有巨大潜力。然而，阐明其“鸡尾酒效应”的内在催化机制仍然是一个巨大挑战，而且也缺乏定量描述符来表征特定的催化活性并为高熵体系提供合理的设计策略。在此，报道了高熵Cu-Co-Fe-Ag-Mo（氧）氢氧化物中所有金属位点对析氧反应（OER）的意外激活，并且发现金属-氧d-p杂化作为一种有效的描述符，可以指示每个金属位点的本征活性。根据定量杂化，提出并验证了引入电子供体（例如Ag）以增强高熵体系的电催化活性。因此，通过电化学重构方法构建了Ag修饰的Co-Cu-Fe-Ag-Mo（氧）氢氧化物（Ag@CoCuFeAgMoOOH）电催化剂，并对其OER性能进行了全面表征。Ag@CoCuFeAgMoOOH被证实具有低过电位（在100 mA cm时为270 mV）和小的塔菲尔斜率（35.3 mV dec）以及良好的电化学稳定性。证明并揭示了电子供体的良好活性和潜在的协同“鸡尾酒效应”。这项工作开辟了一种指导先进高熵电催化剂设计/制备的新策略。
