Enhancing CO2 Electroreduction Performance through Si-Doped CuO: Stabilization of Cu+/Cu0 Sites and Improved C2 Product Selectivity

作者：Long Cheng, Rong Wang, Wenzhe Si, Yanxi Deng, Junhua Li, Yue Peng · 发表于：ACS Catalysis · 年份：2024 · DOI：10.1021/acscatal.4c01961 · 被引用次数：64 · 研究领域：CO2 Reduction Techniques and Catalysts、Ionic liquids properties and applications、Copper-based nanomaterials and applications

Cu-based catalysts leveraging Cu + /Cu 0 active sites have emerged as pivotal for synthesizing essential hydrocarbons and alcohols in electrochemical CO 2 reduction, such as ethylene and ethanol (C 2 products). However, the dynamic reduction of Cu + to Cu 0 during electroreduction leads to site instability, resulting in diminished efficiency for CO 2 conversion to C 2 products. Herein, we introduced Si into CuO by the selective dissolution method, engendering Cu–O–Si units to stabilize the Cu + /Cu 0 sites. The catalyst manifested good activity in CO 2 electroreduction with an elevated Faradaic efficiency for C 2 products reaching 81.9% at −100 mA/cm 2 . After ten cycles of electrochemical testing, the Cu + /Cu 0 sites and performance exhibited no signs of degradation. The Si incorporation significantly improved the hybridization of O 2p and Cu 3d orbitals, thereby reinforcing the Cu–O bonds and stabilizing the Cu + /Cu 0 sites, which was critical in promoting C–C coupling via decreasing the energy barriers for *OCCO formation and enhancing C 2 product selection. The active Cu + cations with unsaturated coordination contributed to the reaction stabilization, thereby improving the preservation of Cu 2 O metastable state.