Metal-organic framework-derived cupric oxide polycrystalline nanowires for selective carbon dioxide electroreduction to C2 valuables

Carbon dioxide (CO2) electroreduction is promising for balancing the carbon cycle for a sustainable society. However, an efficient electrocatalyst is the key to selectively converting CO2 and generating valuable products. In this work, metal-organic framework (MOF) derived porous cupric oxide nanowires are prepared by a controllable annealing method for the efficient CO2 reduction. These polycrystalline nanocatalysts demonstrate a high Faradaic efficiency (FE) of ∼70% for C2 products at -1.3 V vs. RHE. A partial current density of ∼141 mA cm-2 for ethylene with a FE of ∼37% is achieved in a home-made flow cell at -1.3 V vs. RHE. The in situ/ex situ investigations indicate that the oxide-derived metallic copper with abundant interfaces would be the real active sites for highly selective CO2 electrolysis. This work offers effective copper catalysts to selectively convert CO2 toward valuable products, and more importantly provides insightful understanding of developing efficient catalytic materials for energy conversion.