Evoking C2+ production from electrochemical CO2 reduction by the steric confinement effect of ordered porous Cu2O

• Published in: Chemical science (Cambridge) 2023-12, Vol.14 (47), p.13851-13859
• Main Authors: Fan, Longlong, Geng, Qinghong, Ma, Lian, Wang, Chengming, Jun-Xuan, Li, Zhu, Wei, Shao, Ruiwen, Li, Wei, Xiao, Feng, Yamauchi, Yusuke, Li, Cuiling, Jiang, Lei
• Format: Article
• Language: English
• Subjects: Carbon dioxide; Carbon monoxide; Chemical reactions; Chemical synthesis; Copper oxides; Current density; Dimerization; Electrocatalysts; Hydrogen evolution; Reduction
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/d3sc04840c

Selective conversion of carbon dioxide (CO2) to multi-carbon products (CO2-to-C2+) at high current densities is in essential demand for the practical application of the resultant valuable products, yet it remains challenging to conduct due to the lack of efficient electrocatalysts. Herein, three-dimensional ordered porous cuprous oxide cuboctahedra (3DOP Cu2O–CO) were designed and synthesized by a molecular fence-assisted hard templating approach. Capitalizing on the merits of interconnected and uniformly distributed pore channels, 3DOP Cu2O–CO exhibited outstanding electrochemical CO2-to-C2+ conversion, achieving faradaic efficiency and partial current density for C2+ products of up to 81.7% and −0.89 A cm−2, respectively, with an optimal formation rate of 2.92 mmol h−1 cm−2 under an applied current density of −1.2 A cm−2. In situ spectroscopy and simulation results demonstrated that the ordered pores of 3DOP Cu2O–CO can effectively confine and accumulate sufficient *CO adsorption during electrochemical CO2 reduction, which facilitates efficient dimerization for the formation of C2+ products. Furthermore, the 3DOP structure induces a higher local pH value, which not only enhances the C–C coupling reaction, but also suppresses competing H2 evolution.