CO2 electroreduction to multicarbon products from carbonate capture liquid
Geonhui Lee, Armin Sedighian Rasouli, Byoung‐Hoon Lee, Jinqiang Zhang, Da Hye Won, Yurou Celine Xiao, Jonathan P. Edwards, Mi Gyoung Lee, Eui Dae Jung, Fatemeh Arabyarmohammadi, Hengzhou Liu, Ivan Grigioni, Jehad Abed, Tartela Alkayyali, Shijie Liu, Ke Xie, Rui Kai Miao, Sungjin Park, Roham Dorakhan, Yong Zhao, Colin P. O’Brien, Zhu Chen, David Sinton, Edward H. Sargent
Abstract
Alkali hydroxide systems capture CO 2 as carbonate; however, generating a pure CO 2 stream requires significant energy input, typically from thermal cycling to 900°C. What is more, the subsequent valorization of gas-phase CO 2 into products presents additional energy requirements and system complexities, including managing the formation of (bi)carbonate in an electrolyte and separating unreacted CO 2 downstream. Here, we report the direct electrochemical conversion of CO 2 , captured in the form of carbonate, into multicarbon (C 2+ ) products. Using an interposer and a Cu/CoPc-CNTs electrocatalyst, we achieve 47% C 2+ Faradaic efficiency at 300 mA cm −2 and a full cell voltage of 4.1 V. We report 56 wt % of C 2 H 4 and no detectable C 1 gas in the product gas stream: CO, CH 4 , and CO 2 combined total below 0.9 wt % (0.1 vol %). This approach obviates the need for energy to regenerate lost CO 2 , an issue seen in prior CO 2 -to-C 2+ reports.