Electrocatalytic CO2 reduction to alcohols by modulating the molecular geometry and Cu coordination in bicentric copper complexes

• Published in: Nature communications 2022-08, Vol.13 (1), p.5122-5122, Article 5122
• Main Authors: Yang, Baiyu, Chen, Ling, Xue, Songlin, Sun, Hao, Feng, Kun, Chen, Yufeng, Zhang, Xiang, Xiao, Long, Qin, Yongze, Zhong, Jun, Deng, Zhao, Jiao, Yan, Peng, Yang
• Format: Article
• Language: English
• Subjects: 140/131; 140/146; 140/58; 147/135; 147/137; 147/143; 639/301/299/921; 639/638/161/886; 639/638/77/886; Alcohol; Alcohols; Carbon cycle; Carbon dioxide; Chemical reactions; Chemical reduction; Confined spaces; Coordination; Copper; Copper compounds; Electrochemical analysis; Electrochemistry; Electrolysis; Ethanol; Exploitation; Humanities and Social Sciences; Hybrid structures; Hybrids; Intermediates; Ligands; multidisciplinary; Porphyrins; Propanol; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-32740-z

Electrocatalytic reduction of CO 2 into alcohols of high economic value offers a promising route to realize resourceful CO 2 utilization. In this study, we choose three model bicentric copper complexes based on the expanded and fluorinated porphyrin structure, but different spatial and coordination geometry, to unravel their structure-property-performance correlation in catalyzing electrochemical CO 2 reduction reactions. We show that the complexes with higher intramolecular tension and coordination asymmetry manifests a lower electrochemical stability and thus more active Cu centers, which can be reduced during electrolysis to form Cu clusters accompanied by partially-reduced or fragmented ligands. We demonstrate the hybrid structure of Cu cluster and partially reduced O-containing hexaphyrin ligand is highly potent in converting CO 2 into alcohols, up to 32.5% ethanol and 18.3% n- propanol in Faradaic efficiencies that have been rarely reported. More importantly, we uncover an interplay between the inorganic and organic phases to synergistically produce alcohols, of which the intermediates are stabilized by a confined space to afford extra O-Cu bonding. This study underlines the exploitation of structure-dependent electrochemical property to steer the CO 2 reduction pathway, as well as a potential generic tactic to target alcohol synthesis by constructing organic/inorganic Cu hybrids. Electrocatalytic reduction of CO2 into multi-carbon alcohols of high economic merit offers an effective means to close the carbon cycle. Here the authors show the synergy between inorganic and organic phases derived from rationally designed molecular precursors to produce alcohols in high efficiency.