Stabilizing *CO 2 Intermediates at the Acidic Interface using Molecularly Dispersed Cobalt Phthalocyanine as Catalysts for CO 2 Reduction

作者：Shijia Feng, Xiaojun Wang, Dongfang Cheng, Yao Luo, Mengxin Shen, Jingyang Wang, Wei Zhao, Susu Fang, Hongzhi Zheng, Liyao Ji, Xing Zhang, Weigao Xu, Yongye Liang, Philippe Sautet, Jia Zhu · 发表于：Angewandte Chemie International Edition · 年份：2024 · DOI：10.1002/anie.202317942 · 被引用次数：53 · 研究领域：CO2 Reduction Techniques and Catalysts、Ionic liquids properties and applications、Advanced battery technologies research

Abstract CO 2 electroreduction (CO 2 R) operating in acidic media circumvents the problems of carbonate formation and CO 2 crossover in neutral/alkaline electrolyzers. Alkali cations have been universally recognized as indispensable components for acidic CO 2 R, while they cause the inevitable issue of salt precipitation. It is therefore desirable to realize alkali‐cation‐free CO 2 R in pure acid. However, without alkali cations, stabilizing *CO 2 intermediates by catalyst itself at the acidic interface poses as a challenge. Herein, we first demonstrate that a carbon nanotube‐supported molecularly dispersed cobalt phthalocyanine (CoPc@CNT) catalyst provides the Co single‐atom active site with energetically localized d states to strengthen the adsorbate‐surface interactions, which stabilizes *CO 2 intermediates at the acidic interface (pH=1). As a result, we realize CO 2 conversion to CO in pure acid with a faradaic efficiency of 60 % at pH=2 in flow cell. Furthermore, CO 2 is successfully converted in cation exchanged membrane‐based electrode assembly with a faradaic efficiency of 73 %. For CoPc@CNT, acidic conditions also promote the intrinsic activity of CO 2 R compared to alkaline conditions, since the potential‐limiting step, *CO 2 to *COOH, is pH‐dependent. This work provides a new understanding for the stabilization of reaction intermediates and facilitates the designs of catalysts and devices for acidic CO 2 R.