In this work, we introduce a modified dip-and-pull electrochemical X-ray photoelectron spectroscopy (ECXPS) approach that offers new mechanistic insight into the alkaline carbon monoxide reduction reaction (CORR) over a Cu(111) single crystal surface. We tackle two major unresolved questions in the CORR mechanism that persist in the literature. Firstly, we address the mechanism for methane formation on Cu(111) and show that the mechanism likely proceeds via atomic carbon, which subsequently couples, leading to the accumulation of amorphous carbon on the surface. Secondly, we provide insight into whether the mechanism for acetate formation occurs entirely on the surface or partially within the solution phase, showing that acetate is present on the surface, indicating a surface-based reaction. These insights into surface-based mechanisms provide a handle for designing future catalysts that can efficiently target the binding of specific intermediates. Furthermore, we expect that our modified approach to dip-and-pull ECXPS - in which we have changed the electrode geometry, the method of introducing the reactant gas, and used hard x-rays - will significantly expand the technique’s applicability, enabling studies of the CO(2)RR and beyond.

中文翻译：

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从原位电化学 X 射线光电子能谱深入了解 Cu（111） 上的一氧化碳还原反应

在这项工作中，我们引入了一种改进的浸拉电化学 X 射线光电子能谱 （ECXPS） 方法，该方法为 Cu（111） 单晶表面上的碱性一氧化碳还原反应 （CORR） 提供了新的机理见解。我们解决了文献中持续存在的 CORR 机制中的两个主要未解决的问题。首先，我们解决了 Cu（111） 上形成甲烷的机制，并表明该机制可能通过原子碳进行，随后耦合，导致无定形碳在表面积累。其次，我们深入了解了乙酸盐形成的机制是完全发生在表面还是部分发生在溶液相中，表明乙酸盐存在于表面，表明基于表面的反应。这些对基于表面的机制的见解为设计能够有效靶向特定中间体结合的未来催化剂提供了参考。此外，我们预计我们改进的浸拉式 ECXPS 方法（其中我们改变了电极几何形状、引入反应气体的方法并使用了硬 X 射线）将显着扩展该技术的适用性，使 CO（2）RR 及其他研究成为可能。