Modulating CO2 electroreduction pathways through controlled ionomer arrangement on catalyst surfaces via solvent dispersion
Yaoyu Yin, Zhongnan Ling, Shiqiang Liu, Jiapeng Jiao, Meng Zhou, Peigen Zhang, Xing Tong, Yueqian Fan, Jiahao Yang, Huanyan Liu, Xueqing Xing, Jianling Zhang, Yidong Xu, Hongyan Liang, Xinchen Kang, Buxing Han
Abstract
Ionomers play a vital role in the preparation of electrodes for CO 2 electroreduction, and controlling the ionomer configuration on the catalyst surface offers an effective strategy for adjusting the surface microenvironment of the electrode, thereby influencing the distribution of CO 2 electroreduction products. In this study, we demonstrate that Nafion, a commonly used ionomer, exhibits distinct aggregation behaviors in solvents with different dielectric constant (ε) values. These differences in aggregation result in varied Nafion arrangements on the catalyst surface, which in turn affect the binding of ∗CO and ∗H intermediates, enabling control over product distribution. For example, over a Cu nanosheet catalyst at 800 mA cm −2 , the Faradaic efficiency for multicarbon products increases from 67.5% to 90.5% simply by changing the dispersion solvent from low-ε dimethyl sulfoxide to moderate-ε isopropanol. This work introduces a novel approach for fine-tuning CO 2 electroreduction product distribution through manipulation of the dispersion solvent without requiring modifications to the catalyst or ionomer.