Engineering the electronic structure of metal, N-doped carbon catalysts is a potential strategy for increasing the activity and selectivity of CO2 electroreduction reaction (CO2RR). However, establishing a definitive link between structure and performance is extremely difficult due to constrained synthesis approaches that lack the ability to precisely control the specific local environment of M-N-C catalysts. Herein, a soft-template aided technique is developed for the first time to synthesize pyrrolic N4-Ni sites coupled with varying N-type defects to synergistically enhance the CO2RR performance. The optimal catalyst helps attain a CO Faradaic efficiency of 94% at a low potential of −0.6 V and CO partial current density of 59.6 mA cm−2 at −1 V. Results of controlled experimental investigations indicate that the synergy between Ni-N4 and metal free defect sites can effectively promote the CO2RR activity. Theoretical calculations revealed that the pyrrolic N coordinated Ni-N4 sites and C atoms next to pyrrolic N (pyrrolic N-C) have a lower energy barrier for the formation of COOH* intermediate and optimum CO* binding energy. The pyrrolic N regulate the electronic structure of the catalyst, resulting in lower CO2 adsorption energy and higher intrinsic catalytic activity.
Bibliographical noteFunding Information:
This research was supported by the Basic Science Research Program (NRF‐2020R1A4A1017737, 2021R1F1A1048758, and 2022R1A2C3003081) and Regional Leading Research Center Program (2019R1A5A8080326) through the National Research Foundation of Korea (NRF) funded by the Ministry of Education and Ministry of Science and ICT. This work was also supported (in part) by the Yonsei University Research Fund (Yonsei Frontier Lab. Young Researcher Supporting Program) of 2020.
© 2022 Wiley-VCH GmbH.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics