Chen Xiao, Jia Shuaiqiang, Zhai Jianxin, Jiao Jiapeng, Dong Mengke, Xue Cheng, Deng Ting, Cheng Hailian, Xia Zhanghui, Chen Chunjun, Xing Xueqing, Zeng Jianrong, Wu Haihong, He Mingyuan, Han Buxing
Shanghai Key Laboratory of Green Chemistry and Chemical Processes, State Key Laboratory of Petroleum Molecular & Process Engineering, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, China.
Institute of Eco-Chongming, 20 Cuiniao Road, Chenjia Town, Chongming District, Shanghai, China.
Nat Commun. 2024 Sep 3;15(1):7691. doi: 10.1038/s41467-024-51928-z.
Copper (Cu)-based catalysts show promise for electrocatalytic CO reduction (CORR) to multi-carbon alcohols, but thermodynamic constraints lead to competitive hydrocarbon (e.g., ethylene) production. Achieving selective ethanol production with high Faradaic efficiency (FE) and current density is still challenging. Here we show a multivalent Cu-based catalyst, Cu-2,3,7,8-tetraaminophenazine-1,4,6,9-tetraone (Cu-TAPT) with Cu and Cu atomic ratio of about 1:2 for CORR. Cu-TAPT exhibits an ethanol FE of 54.3 ± 3% at an industrial-scale current density of 429 mA cm, with the ethanol-to-ethylene ratio reaching 3.14:1. Experimental and theoretical calculations collectively unveil that the catalyst is stable during CORR, resulting from suitable coordination of the Cu and Cu with the functional groups in TAPT. Additionally, mechanism studies show that the increased ethanol selectivity originates from synergy of multivalent Cu sites, which can promote asymmetric C-C coupling and adjust the adsorption strength of different carbonaceous intermediates, favoring hydroxy-containing C intermediate (*HCCHOH) formation and formation of ethanol.
铜（Cu）基催化剂在电催化将一氧化碳还原（CORR）为多碳醇方面展现出前景，但热力学限制导致竞争性的碳氢化合物（如乙烯）生成。实现具有高法拉第效率（FE）和电流密度的选择性乙醇生产仍然具有挑战性。在此，我们展示了一种多价铜基催化剂，即铜与铜原子比约为1:2的2,3,7,8 - 四氨基吩嗪 - 1,4,6,9 - 四酮（Cu - TAPT）用于CORR。在429 mA cm的工业规模电流密度下，Cu - TAPT表现出54.3±3%的乙醇法拉第效率，乙醇与乙烯的比例达到3.14:1。实验和理论计算共同揭示，该催化剂在CORR过程中是稳定的，这源于Cu和Cu与TAPT中的官能团的合适配位。此外，机理研究表明，乙醇选择性的提高源于多价铜位点的协同作用，其可以促进不对称碳 - 碳偶联并调节不同含碳中间体的吸附强度，有利于含羟基的C中间体（*HCCHOH）的形成以及乙醇的生成。
