Manipulation of Oxygen Species on an Antimony-Modified Copper Surface to Tune the Product Selectivity in CO<sub>2</sub> Electroreduction
Pengsong Li, Jiyuan Liu, Yong Wang, Xiang‐Da Zhang, Yuqing Hou, Yichao Zhang, Xiaofu Sun, Xinchen Kang, Qinggong Zhu, Buxing Han
Abstract
High Resolution Image Download MS PowerPoint Slide Rational regulation of the electrochemical CO 2 reduction reaction (CO 2 RR) pathway to produce desired products is particularly interesting, yet designing economical and robust catalysts is crucial. Here, we report an antimony-modified copper (CuSb) catalyst capable of selectively producing both CO and multicarbon (C 2+ ) products in the CO 2 RR. At a current density of 0.3 A/cm 2, the faradaic efficiency (FE) of CO was as high as 98.2% with a potential of −0.6 V vs reversible hydrogen electrode (RHE). When the current density increased to 1.1 A/cm 2 at −1.1 V vs RHE, the primary products shifted to C 2+ compounds with a FE of 75.6%. Experimental and theoretical studies indicate that tuning the potential could manipulate the oxygen species on the CuSb surface, which determined the product selectivity in the CO 2 RR. At a more positive potential, the existence of oxygen species facilitates the potential-limiting step involving *COOH formation and reduces the adsorption of *CO intermediates, thereby promoting CO production. At a more negative potential, the localized high CO concentration coupled with the enhanced adsorption of *CO intermediates due to Sb incorporation facilitates C–C coupling and deep hydrogenation processes, resulting in an increased C 2+ selectivity.