Cu(2)O Nanoparticles with Both {100} and {111} Facets for Enhancing the Selectivity and Activity of CO(2) Electroreduction to Ethylene

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.