Localized mass transport channels for electro-upgrade of dilute CO2 toward high-yield C2+ products
Bohua Ren, Xiaowen Zhang, Leixin Yang, Guobin Wen, Silong Dong, Haoyang Xiong, Yiyin Liu, Xiaoman Duan, Lichao Tan, Xin Wang, Zhongwei Chen
Abstract
Electrocatalytic upgrade of CO2 offers a promising approach for recycling of global CO2 emissions, facilitating the achievement of carbon neutrality. Nevertheless, direct utilization of practical dilute CO2 is urgently important yet rather difficult, which is hindered by the balance of reaction kinetics and mass transport of CO2 to the catalytic sites. Herein, we propose coordinating the local environment and active catalyst by constructing covalent organic frameworks (COF) on single-atomic In-doped Cu2O (In1@Cu2O) for a high tolerance of CO2 inlet concentrations (15% to 100%). The optimized amounts of COF functionalized by the trifluoromethyl group act as the local CO2/CO diffusion channels via steric confinement effects and C···F electronic effects. Besides, the formation of key intermediates for C2+ products is greatly facilitated by the promoted COOH adsorption. Hence, a total current of 81.7 A is realized in a 4 × 100 cm2 electrolyzer stack with over 770 mmol/h C2+ products at an inlet of dilute CO2. Such a electrode architecture sheds light on the dilute CO2 electrolysis at the potential industrial scale. The continuous dilute CO2 electrolysis is promising for industrial applications but limited by high resistance of mass transport. Here, the authors report a localized mass transport channels coupling CO2 concentrating and converting process to synthesize highly selective and stable C2+ products.