Oxygen‐Substituted Porous C<sub>2</sub>N Frameworks as Efficient Electrocatalysts for Carbon Dioxide Electroreduction
Shuai Wang, Shujie Zhou, Zhipeng Ma, Nana Gao, Rahman Daiyan, Josh Leverett, Yihao Shan, Xiaofeng Zhu, Yufei Zhao, Qiang Liu, Rose Amal, Xunyu Lu, Tianxi Liu, Markus Antonietti, Yinguang Chen, Qingran Zhang, Zhihong Tian
Abstract
Abstract The electrochemical carbon dioxide reduction reaction (CO 2 RR) provides a green avenue for decarbonizing the conventional chemical industries. Here, a structure–selectivity relationship of catalysts is pivotal for the control of a highly selective and active CO 2 RR pathway. We report the fabrication of an oxygen‐substituted C 2 N as metal‐free catalyst (O─C 2 N) for electrochemical CO 2 ─to─CO conversion with tunable O microenvironment. Combined spectroscopic analysis reveals a fine tailored N─C─O moiety in O─C 2 N, where C─O─C species (e.g., ring in‐plane ether) become the dominant oxygen configurations at higher pyrolysis temperatures. Based on experimental observations, a correlation between the exocyclic O‐substituted N─C─O─C moieties and CO selectivity is established, giving clear chemical tools for active structure design. The optimized O─C 2 N electrocatalysts with the dominant appearance of C─O─C moieties exhibit an outstanding 2e − CO 2 RR performance with a CO selectivity up to 94.8%, which can be well maintained in a practical flow‐cell reactor with an adjustable syngas feature.