Chen Chunjun, Yan Xupeng, Wu Yahui, Liu Shoujie, Sun Xiaofu, Zhu Qinggong, Feng Rongjuan, Wu Tianbin, Qian Qingli, Liu Huizhen, Zheng Lirong, Zhang Jing, Han Buxing
Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Colloid and Interface and Thermodynamics, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences Beijing 100190 P. R. China
University of Chinese Academy of Sciences Beijing 100049 China.
Chem Sci. 2021 Mar 16;12(16):5938-5943. doi: 10.1039/d1sc00042j. eCollection 2021 Apr 28.
Oxide-derived copper (OD-Cu) has been discovered to be an effective catalyst for the electroreduction of CO to C2+ products. The structure of OD-Cu and its surface species during the reaction process are interesting topics, which have not yet been clearly discussed. Herein, surface-enhanced Raman spectroscopy (SERS), operando X-ray absorption spectroscopy (XAS), and O isotope labeling experiments were employed to investigate the surface species and structures of OD-Cu catalysts during CO electroreduction. It was found that the OD-Cu catalysts were reduced to metallic Cu(0) in the reaction. CuO species existed on the catalyst surfaces during the CORR, which resulted from the adsorption of preliminary intermediates (such as *CO and *OCO) on Cu instead of on the active sites of the catalyst. It was also found that abundant interfaces can be produced on OD-Cu, which can provide heterogeneous CO adsorption sites (strong binding sites and weak binding sites), leading to outstanding performance for obtaining C2+ products. The Faradaic efficiency (FE) for C2+ products reached as high as 83.8% with a current density of 341.5 mA cm at -0.9 V RHE.
已发现氧化物衍生铜（OD-Cu）是将CO电还原为C2+产物的有效催化剂。OD-Cu的结构及其在反应过程中的表面物种是有趣的课题，尚未得到清晰的讨论。在此，采用表面增强拉曼光谱（SERS）、原位X射线吸收光谱（XAS）和O同位素标记实验来研究OD-Cu催化剂在CO电还原过程中的表面物种和结构。研究发现，OD-Cu催化剂在反应中被还原为金属Cu(0)。在CO还原反应（CORR）过程中，催化剂表面存在CuO物种，这是由初级中间体（如CO和OCO）吸附在Cu上而非催化剂活性位点上导致的。还发现OD-Cu上可产生大量界面，能提供异质CO吸附位点（强结合位点和弱结合位点），从而在获得C2+产物方面表现出色。在-0.9 V RHE下，C2+产物的法拉第效率（FE）高达83.8%，电流密度为341.5 mA cm。
