Multi-shelled CuO microboxes for carbon dioxide reduction to ethylene

The electroreduction of CO₂ to valuable chemicals and fuels offers an effective mean for energy storage. Although CO₂ has been efficiently converted into C₁ products (e.g., carbon monoxide, formic acid, methane and methanol), its convention into high value-added multicarbon hydrocarbons with high selectivity and activity still remains challenging. Here we demonstrate the formation of multi-shelled CuO microboxes for the efficient and selective electrocatalytic CO₂ reduction to C₂H₄. Such a structure favors the accessibility of catalytically active sites, improves adsorption of reaction intermediate (CO), inhibits the diffusion of produced OH^- and promotes C-C coupling reaction. Owing to these unique advantages, the multi-shelled CuO microboxes can effectively convert CO₂ into C₂H₄ with a maximum faradaic efficiency of 51.3% in 0.1 M K₂SO₄. This work provides an effective way to improve CO₂ reduction efficiency via constructing micro- and nanostructures of electrocatalysts.