Exclusive Co‐N4 Sites Confined in Two‐dimensional Metal‐Organic Layers Enabling Highly Selective CO2 Electroreduction at Industrial‐Level Current

• Published in: Angewandte Chemie International Edition Vol. 62; no. 23; pp. e202219241 - n/a
• Main Authors: Zhang, Wenjun, Liu, Shanshan, Yang, Yue, Qi, Haifeng, Xi, Shibo, Wei, Yanping, Ding, Jie, Wang, Zhu‐Jun, Li, Qunxiang, Liu, Bin, Chen, Zupeng
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 05.06.2023
• Edition: International ed. in English
• Subjects: Adsorption; Bottom-up Method; Carbon dioxide; Carbon monoxide; Catalysts; Co-N4 Sites; CO2 Reduction; Density functional theory; Electrical conductivity; Electrical resistivity; Electrodes; Electrolysis; Electrowinning; MEA Device; Porphyrin Porous Organic Layers; Porphyrins
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202219241

Metal‐organic framework catalysts bring new opportunities for CO2 electrocatalysis. Herein, we first conduct density‐functional theory calculations and predict that Co‐based porphyrin porous organic layers (Co‐PPOLs) exhibit good activity for CO2 conversion because of the low *CO adsorption energy at Co‐N4 sites, which facilitates *CO desorption and CO formation. Then, we prepare two‐dimensional Co‐PPOLs with exclusive Co‐N4 sites through a facile surfactant‐assisted bottom‐up method. The ultrathin feature ensures the exposure of catalytic centers. Together with large specific area, high electrical conductivity and CO2 adsorption capability, Co‐PPOLs achieve a peak faradaic efficiency for CO production (FECO=94.2 %) at a moderate potential in CO2 electroreduction, accompanied with good stability. Moreover, Co‐PPOLs reach an industrial‐level current above 200 mA in a membrane electrode assembly reactor, and maintain near‐unity CO selectivity (FECO>90 %) over 20 h in CO2 electrolysis. Together with the exclusive Co‐N4 sites, enlarged surface area, improved electrical conductivity and CO2 adsorption capacity, Co porphyrin‐based porous organic layers exhibit optimal activity for electrochemical CO2 reduction to CO due to the strong *COOH binding and moderate *CO adsorption. Moreover, industrial‐level current above 200 mA can be achieved in a membrane electrode assembly device with near‐unity CO selectivity over 20 h.