Herein, we present the surface electronic structure and morphological evolution under reduction and oxidation conditions for Pd@Co (PC) core‐shell nanoparticles with different Pd : Co ratio (PC=2 : 1, 1 : 1 and 1 : 2). Extensive measurements have been made with NAPXPS (near ambient pressure x‐ray photoelectron spectroscopy) under oxidising and reducing conditions, and ex‐situ HRTEM. It has been demonstrated that PC catalysts are thermally stable towards morphological changes, at least up to 575 K. Nonetheless, it shows a significant surface electronic structure changes under reaction environments, which are highly relevant to heterogeneous catalysis. As expected, high (low) population of metallic (oxidised) Co was observed, while retaining core shell structure under reduction (H₂ and vacuum annealing) environment. Interestingly, the Pd−Co metallic interface helps to overcome the pyrophoric nature of cobalt and stabilised a significant amount of metallic Co at Pd−Co interface even in the presence of 0.1 mbar O₂ up to 575 K. The presence of Pd−Co and Pd−Co@Co₃O₄ interfaces in reaction environment makes the catalyst dual functional. The proof of concept has been explored in terms of oxidation of CO in the presence of H₂ or O₂.

中文翻译：

---

Pd @ Co纳米催化剂在氧化还原条件和优先CO氧化作用下的电子结构演化

在此，我们介绍了具有不同Pd：Co比（PC = 2：1、1：1：1和1：2）的Pd @ Co（PC）核壳纳米粒子在还原和氧化条件下的表面电子结构和形态演变。在氧化和还原条件下，使用NAPXPS（近环境压力X射线光电子能谱）和异位HRTEM进行了广泛的测量。已证明PC催化剂对形态变化具有热稳定性，至少在575 K以下是稳定的。尽管如此，它在反应环境下仍显示出明显的表面电子结构变化，这与多相催化高度相关。如预期的那样，观察到高（低）金属（氧化）Co族，同时保留了还原状态下的核壳结构（H ₂和真空退火）环境。有趣的是，Pd-Co金属界面有助于克服钴的自燃性质，即使在存在高达575 K的0.1 mbar O ₂的情况下，也能稳定Pd-Co界面处的大量金属Co。反应环境中的Pd-Co @ Co ₃ O ₄界面使催化剂具有双重功能。已经在存在H ₂或O ₂的情况下对CO的氧化进行了概念验证。