The lack of direct insight into the microstructural evolution of catalytic materials under electrochemical polarization has inhibited the development of heterogeneous catalysts. By investigating a typical Au@Pd core–shell nanostructure, the present study discloses the microstructural evolution of heterogeneous catalytic materials during the methanol electrooxidation reaction (MOR). The electrocatalytic activity of the as-prepared Au@Pd_core–shell nanoparticles continuously increased during the first 100 successive voltammetry cycles of the MOR. Microstructural characterization studies revealed that during the MOR, an Au/Pd mixed bimetallic shell was formed by the self-driven microstructural evolution of the Au@Pd_core–shell nanoparticles. Both the experimental and calculation results indicated that the Au/Pd mixed bimetallic shell reduced the binding strength of OH⁻ and CO on the catalyst surface. The exposed Au atoms in the shell region also produced large-scale reactive ˙OH radicals that facilitated the oxidative removal of the adsorbed carbonaceous species from the adjacent Pd active sites.

中文翻译：

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Au @ Pd核壳纳米粒子的自驱动微观结构演变，可大大增强甲醇电氧化过程中的催化性能

缺乏对电化学极化作用下催化材料的微观结构演变的直接了解，已抑制了非均相催化剂的发展。通过研究典型的Au @ Pd核壳纳米结构，本研究揭示了甲醇电氧化反应（MOR）过程中非均相催化材料的微观结构演变。在MOR的前100个连续伏安循环中，所制备的Au @ Pd_core-shell纳米粒子的电催化活性不断提高。微观结构表征研究表明，在MOR期间，Au @ Pd_core-shell纳米粒子的自驱动微观结构演变形成了Au / Pd混合双金属壳。^-和催化剂表面上的CO。壳区域中暴露的Au原子还产生大规模的反应性OH自由基，有助于从相邻的Pd活性位点上氧化除去吸附的碳质物质。