1. Substituent tuning of Cu coordination polymers enables carbon-efficient CO2 electroreduction to multi-carbon products
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Huiying Deng, Tingting Liu, Wenshan Zhao, Jundong Wang, Yuesheng Zhang, Shuzhen Zhang, Yu Yang, Chao Yang, Wenzhi Teng, Zhuo Chen, Gengfeng Zheng, Fengwang Li, Yaqiong Su, Jingshu Hui, and Yuhang Wang
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Science - Abstract
Abstract CO2 electroreduction is a potential pathway to achieve net-zero emissions in the chemical industry. Yet, CO2 loss, resulting from (bi)carbonate formation, renders the process energy-intensive. Acidic environments can address the issue but at the expense of compromised product Faradaic efficiencies (FEs), particularly for multi-carbon (C2+) products, as rapid diffusion and migration of protons (H+) favors competing H2 and CO production. Here, we present a strategy of tuning the 2-position substituent length on benzimidazole (BIM)-based copper (Cu) coordination polymer (CuCP) precatalyst – to enhance CO2 reduction to C2+ products in acidic environments. Lengthening the substituent from H to nonyl enhances H+ diffusion retardation and decreases Cu-Cu coordination numbers (CNs), favoring further reduction of CO. This leads to a nearly 24× enhancement of selectivity towards CO hydrogenation and C-C coupling at 60 mA cm−2. We report the highest C2+ product FE of more than 70% at 260 mA cm−2 on pentyl-CuCP and demonstrate a CO2-to-C2+ single-pass conversion (SPC) of ~54% at 180 mA cm−2 using pentyl-CuCP in zero-gap electrolyzers.
- Published
- 2024
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