The thermal treatment of bimetallic nanocatalysts plays an important role in determining their catalytic performance. Here tuning the surface oxidized metal species of bimetallic Pd–Fe electrocatalysts for the formic acid (FA) oxidation reaction is reported and a correlation between the surface oxidized metal species of the Pd–Fe nanoparticles and their catalytic activities is proposed. The structural details of the Pd–Fe/C catalysts are characterized by X-ray diffraction, X-ray photoelectron spectroscopy and high-sensitivity low-energy ion scattering (HS-LEIS). Cyclic voltammetry measurements demonstrated that the mass activity of the Pd–Fe nanoparticles with a molar ratio of Pd/Fe = 1/15 is about 7.4 times higher than that of Pd/C. This enhancement could be attributed to the synergistic effect between Pd(0) and Pd oxidized species on the surface of the Pd–Fe/C treated sample and electronic effects. This finding demonstrates the importance of surface oxidized metal species at the nanoscale in harnessing the true electrocatalytic potential of bimetallic nanoparticles and opens up strategies for the development of highly active bimetallic nanoparticles for electrochemical energy conversion.

中文翻译：

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Pd修饰的Fe/C纳米催化剂的热处理对其甲酸氧化催化性能的影响

双金属纳米催化剂的热处理在决定其催化性能方面起着重要作用。本文报道了调整用于甲酸（FA）氧化反应的双金属 Pd-Fe 电催化剂的表面氧化金属物质，并提出了 Pd-Fe 纳米颗粒的表面氧化金属物质与其催化活性之间的相关性。Pd-Fe/C 催化剂的结构细节通过 X 射线衍射、X 射线光电子能谱和高灵敏度低能离子散射 (HS-LEIS) 表征。循环伏安法测量表明，摩尔比为 Pd/Fe = 1/15 的 Pd-Fe 纳米颗粒的质量活度比 Pd/C 高约 7.4 倍。这种增强可归因于 Pd-Fe/C 处理样品表面上 Pd(0) 和 Pd 氧化物质之间的协同效应和电子效应。这一发现证明了纳米级表面氧化金属物质在利用双金属纳米粒子的真正电催化潜力方面的重要性，并为开发用于电化学能量转换的高活性双金属纳米粒子开辟了策略。