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

Abstract

Cu₂O nanoparticles (NPs) enclosed with different crystal facets, namely, c-Cu₂O NPs with {100} facets, o-Cu₂O NPs with {111} facets, and t-Cu₂O NPs with both {111} and {100} facets, are prepared and their electrocatalytic properties for the reduction of CO₂ to C₂H₄ are evaluated. It is shown that the selectivity and activity of the C₂H₄ production depend strongly on the crystal facets exposed in Cu₂O NPs. The selectivities for the C₂H₄ production increases in the order, c-Cu₂O < o-Cu₂O < t-Cu₂O, (with FE_C2H4 = 38%, 45%, and 59%, respectively). This study suggests that Cu₂O NPs are more likely responsible for the selectivity and activity for the C₂H₄ production than the metallic Cu NPs produced on the surface of Cu₂O NPs. This work provides a new route for enhancing the selectivity of the electrocatalytic CO₂ reduction by crystal facet engineering.