Operando X-ray Raman Studies of Oxide Derived Copper to Uncover the Carbon Dioxide Reduction Mechanism

This study aims to elucidate the operational mechanism of highly active electrocatalysts for CO2 reduction (CO2R) through operando X-ray Raman Scattering (XRS) at high current densities. By utilising the O K-edge and transition metal (TM) L-edges as probes of TM-O hybridisation, we seek to uncover the mechanism of the CO2R reaction. The short attenuation length of soft X-rays limits the operando studies with soft X-ray Absorption Spectroscopy; thus, we developed a novel cell to enhance gas mass transport at the electrode surface. Our investigations focuses on copper-based electrodes to understand operational mechanisms at high potentials linked to C2+ product formation. This research is crucial for improving the selectivity and stability of CO2R catalysts, promoting the industrial use of electrochemical processes for energy-dense products. We aim to utilise XRS for operando measurements of TM and O redox processes in CO2R to advance knowledge of the reaction mechanism.

本研究旨在通过高电流密度下的原位X射线拉曼散射（operando X-ray Raman Scattering, XRS），阐明用于二氧化碳还原（CO2 reduction, CO2R）的高活性电催化剂的反应运行机制。本研究以O K边与过渡金属（transition metal, TM）L边作为过渡金属-氧（TM-O）杂化的探测探针，以期揭示CO₂还原反应的机理。由于软X射线的衰减长度较短，限制了软X射线吸收光谱的原位研究，因此我们开发了一种新型电解池以强化电极表面的气体传质过程。本研究聚焦于铜基电极，以探究与C2+产物生成相关的高电位下的反应运行机制。此项研究对于提升CO₂还原电催化剂的选择性与稳定性、推动高能量密度产物电化学转化工艺的工业化应用具有关键意义。我们旨在通过XRS开展CO₂还原过程中过渡金属与氧的氧化还原反应的原位检测，以深化对该反应机理的认知。