Improving Electrocatalytic CO<sub>2</sub> Reduction over Iron Tetraphenylporphyrin with Triethanolamine as a CO<sub>2</sub> Shuttle
Zhiyuan Yin, Mengchun Zhang, Yuchi Long, Haitao Lei, Xialiang Li, Xuepeng Zhang, Wei Zhang, Ulf‐Peter Apfel, Rui Cao
Abstract
Abstract Delivering CO 2 molecules to catalyst sites is a vital step in the CO 2 reduction reaction (CO 2 RR). Achievements have been made to develop efficient catalysts, but few efforts have been dedicated to improving CO 2 delivering in solutions. Herein, we report on electrocatalytic CO 2 ‐to‐CO conversion using Fe tetraphenylporphyrin (FeTPP) as a catalyst and triethanolamine as a CO 2 shuttle. Compared to ethanol, the electrocatalytic CO 2 RR current with triethanolamine increases by more than three times. We show that triethanolamine can effectively capture a CO 2 molecule to form a zwitterionic alkylcarbonate through the collaboration between its tripodal alcohol and amine units. This alkylcarbonate can release the bound CO 2 molecule for activation at the Fe site upon its interaction with FeTPP. In addition to shuttling CO 2 , alkylcarbonates can also provide protons to assist the C−O bond cleavage. Therefore, this work is significant to demonstrate a new strategy to improve electrocatalytic CO 2 RR by shuttling CO 2 .