Assessment of the Degradation Mechanisms of Cu Electrodes during the CO 2 Reduction Reaction

作者：Rik V. Mom, Luís-Ernesto Sandoval-Díaz, Dunfeng Gao, Cheng‐Hao Chuang, Emilia A. Carbonio, Travis E. Jones, Rosa Arrigo, Danail Ivanov, Michael Hävecker, Beatriz Roldán Cuenya, Robert Schlögl, Thomas Lunkenbein, Axel Knop‐Gericke, Juan‐Jesús Velasco‐Vélez · 发表于：ACS Applied Materials & Interfaces · 年份：2023 · DOI：10.1021/acsami.2c23007 · 被引用次数：35 · 研究领域：CO2 Reduction Techniques and Catalysts、Ionic liquids properties and applications、Electrocatalysts for Energy Conversion

Catalyst degradation and product selectivity changes are two of the key challenges in the electrochemical reduction of CO 2 on copper electrodes. Yet, these aspects are often overlooked. Here, we combine in situ X-ray spectroscopy, in situ electron microscopy, and ex situ characterization techniques to follow the long-term evolution of the catalyst morphology, electronic structure, surface composition, activity, and product selectivity of Cu nanosized crystals during the CO 2 reduction reaction. We found no changes in the electronic structure of the electrode under cathodic potentiostatic control over time, nor was there any build-up of contaminants. In contrast, the electrode morphology is modified by prolonged CO 2 electroreduction, which transforms the initially faceted Cu particles into a rough/rounded structure. In conjunction with these morphological changes, the current increases and the selectivity changes from value-added hydrocarbons to less valuable side reaction products, i.e., hydrogen and CO. Hence, our results suggest that the stabilization of a faceted Cu morphology is pivotal for ensuring optimal long-term performance in the selective reduction of CO 2 into hydrocarbons and oxygenated products.