Cu2O Nanoparticles with Both {100} and {111} Facets for Enhancing the Selectivity and Activity of CO2 Electroreduction to Ethylene

Abstract Cu 2 O nanoparticles (NPs) enclosed with different crystal facets, namely, c‐Cu 2 O NPs with {100} facets, o‐Cu 2 O NPs with {111} facets, and t‐Cu 2 O NPs with both {111} and {100} facets, are prepared and their electrocatalytic properties for the reduction of CO 2 to C 2 H 4 are evaluated. It is shown that the selectivity and activity of the C 2 H 4 production depend strongly on the crystal facets exposed in Cu 2 O NPs. The selectivities for the C 2 H 4 production increases in the order, c‐Cu 2 O < o‐Cu 2 O < t‐Cu 2 O, (with FE C2H4 = 38%, 45%, and 59%, respectively). This study suggests that Cu 2 O NPs are more likely responsible for the selectivity and activity for the C 2 H 4 production than the metallic Cu NPs produced on the surface of Cu 2 O NPs. This work provides a new route for enhancing the selectivity of the electrocatalytic CO 2 reduction by crystal facet engineering.