Highly Efficient Porous Carbon Electrocatalyst with Controllable N‐Species Content for Selective CO2 Reduction

• Published in: Angewandte Chemie International Edition Vol. 59; no. 8; pp. 3244 - 3251
• Main Authors: Ye, Lin, Ying, Yiran, Sun, Dengrong, Zhang, Zhouyang, Fei, Linfeng, Wen, Zhenhai, Qiao, Jinli, Huang, Haitao
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 17.02.2020
• Edition: International ed. in English
• Subjects: Carbon dioxide; Chemical reduction; CO2 reduction; electrocatalysis; Electrocatalysts; hierarchically porous materials; Metal-organic frameworks; metal–organic frameworks (MOFs); nitrogen-doped carbon; Zinc
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201912751

We report a straightforward strategy to design efficient N doped porous carbon (NPC) electrocatalyst that has a high concentration of easily accessible active sites for the CO2 reduction reaction (CO2RR). The NPC with large amounts of active N (pyridinic and graphitic N) and highly porous structure is prepared by using an oxygen‐rich metal–organic framework (Zn‐MOF‐74) precursor. The amount of active N species can be tuned by optimizing the calcination temperature and time. Owing to the large pore sizes, the active sites are well exposed to electrolyte for CO2RR. The NPC exhibits superior CO2RR activity with a small onset potential of −0.35 V and a high faradaic efficiency (FE) of 98.4 % towards CO at −0.55 V vs. RHE, one of the highest values among NPC‐based CO2RR electrocatalysts. This work advances an effective and facile way towards highly active and cost‐effective alternatives to noble‐metal CO2RR electrocatalysts for practical applications. A means to an N: N‐doped porous carbon (NPC) with a hierarchical porous structure and a high concentration of pyridinic‐N and graphitic‐N was prepared by calcinating a mixture of oxygen‐rich Zn‐MOF‐74 and melamine. The optimized NPC shows a high electrocatalytic activity toward CO2 reduction and high selectivity by suppressing hydrogen evolution.