Identification of the activity source of CO2 electroreduction by strategic catalytic site distribution in stable supramolecular structure system

Sheng-Nan Sun; Ning Li; Jiang Liu; Wen-Xin Ji; Long-Zhang Dong; Yi-Rong Wang; Ya-Qian Lan

doi:10.1093/nsr/nwaa195

Identification of the activity source of CO₂ electroreduction by strategic catalytic site distribution in stable supramolecular structure system

Natl Sci Rev. 2020 Aug 31;8(3):nwaa195. doi: 10.1093/nsr/nwaa195. eCollection 2021 Mar.

Authors

Sheng-Nan Sun¹, Ning Li², Jiang Liu¹, Wen-Xin Ji³, Long-Zhang Dong¹, Yi-Rong Wang¹, Ya-Qian Lan¹

Affiliations

¹ Jiangsu Collaborative Innovation Centre of Biomedical Functional Materials, Jiangsu Key Laboratory of New Power Batteries, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, China.
² School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002, China.
³ State Key Laboratory of High-efficiency Coal Utilization and Green Chemical Engineering, Ningxia University, Yinchuan 750021, China.

Abstract

Identification of the real catalytic site in CO₂ reduction reaction (CO₂RR) is critical for the rational design of catalysts and the understanding of reactive mechanisms. In this study, the catalytic activity of pyridine-containing materials was for the first time structurally demonstrated in CO₂RR by crystalline supramolecular coordination compounds model system. The system consists of three stable supramolecular coordination compounds (Ni-TPYP, Ni-TPYP-1 and Ni-TPP) with different numbers (4, 2 and 0) of active pyridine groups (i.e. uncoordinated pyridine nitrogen atoms). The electrocatalytic test results show that with the decrease of the number of active pyridine groups, the CO₂RR performance is gradually reduced, mainly showing the reduction of highest FE_CO (99.8%, 83.7% and 25.6%, respectively). The crystallographic, experimental and theoretical evidences prove that the CO₂RR activity is more likely derived from uncoordinated pyridine nitrogen than the electrocatalytic inert metal nickel in porphyrin center. This work serves as an important case study for the identification of electrocatalytic activity of pyridine-containing materials in CO₂RR by simple supramolecular model system.

Keywords: CO2 electroreduction; active source; strategic catalytic site distribution; supramolecular structure system.