Evoking C 2+ production from electrochemical CO 2 reduction by the steric confinement effect of ordered porous Cu 2 O.
Longlong FanQinghong GengLian MaChengming WangJun-Xuan LiWei ZhuRuiwen ShaoWei LiXiao FengYamauchi YusukeCuiling LiLei JiangPublished in: Chemical science (2023)
Selective conversion of carbon dioxide (CO 2 ) to multi-carbon products (CO 2 -to-C 2+ ) 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 Cu 2 O-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 Cu 2 O-CO exhibited outstanding electrochemical CO 2 -to-C 2+ conversion, achieving faradaic efficiency and partial current density for C 2+ 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 Cu 2 O-CO can effectively confine and accumulate sufficient *CO adsorption during electrochemical CO 2 reduction, which facilitates efficient dimerization for the formation of C 2+ products. Furthermore, the 3DOP structure induces a higher local pH value, which not only enhances the C-C coupling reaction, but also suppresses competing H 2 evolution.