Enhancing CO<sub>2</sub> Electroreduction to Ethylene in Acidic Solution by Optimizing Cation Configuration on the Cu Surface
Yaoyu Yin, Zhongnan Ling, Shiqiang Liu, Jiapeng Jiao, Yiyong Wang, Yaguang Peng, Xing Tong, Meng Zhou, Rongjuan Feng, Xueqing Xing, Yi Xu, Qinggong Zhu, Xiaofu Sun, Mingchuan Luo, Xinchen Kang, Buxing Han
Abstract
The electroreduction of CO 2 to C 2 H 4 offers a promising avenue for advancing carbon neutrality and promoting sustainable chemical manufacturing. In acidic environments, while long-term operational stability and CO 2 utilization efficiency are enhanced, the formation of C–C bonds is hindered due to the weak adsorption of *CO intermediates and the competing hydrogen evolution reaction (HER). Theoretical studies suggest that K + cations with reduced bound water content can strengthen the adsorption of the critical *CO intermediate, and that elevated K + concentrations on the Cu electrode surface significantly facilitate CO 2 electroreduction to C 2 H 4 . In this work, a catalyst termed Cu TEA was developed by strategically modifying the Nafion ionomer distribution within the catalyst layer. This structural adjustment effectively lowers the bound water associated with K + cations and concurrently elevates the surface concentration of K + on the Cu electrode, thereby promoting C–C coupling for C 2 H 4 formation while suppressing HER. Consequently, Cu TEA achieves a Faradaic efficiency of 70.2% for C 2 H 4 production, accompanied by a high partial current density of 561.6 mA cm –2 in an acidic electrolyte (pH = 1).