Highly efficient CO2 reduction on ordered porous Cu electrode derived from Cu2O inverse opals

Abstract Electrochemical reduction of CO 2 to fuels is a promising way to reduce CO 2 emission and address the environment and energy crisis. However, the H 2 evolution reaction competes with CO 2 electrochemical reduction, which would lower the overall efficiency for carbonaceous products. In this work, a new electrocatalyst (cubic-shaped Cu inverse opals) was reported to reduce CO 2 to useful chemicals, which was synthesized from an electrochemical reduction of Cu 2 O inverse opals. The Cu inverse opals could electrochemically reduce CO 2 to CO and HCOOH with a Faradaic efficiency of 45.3% and 33.6%, which was 3 times and 5 times higher than that of Cu particles film at identical conditions. The improved Faradaic efficiency for CO 2 reduction was ascribed to the enhanced stabilization for the CO 2 • − intermediate on the high surface area of Cu inverse opals, and the greatly improved reactant diffusion in this interconnected and ordered macroporous structure. The design of Cu inverse opals presents a prospective application of inverse opals in CO 2 reduction through constructing inverse-opal structure as groundwork, which may provide key structure−activity insights for efficient CO 2 reduction.