Enhancing the electrochemical reduction of carbon dioxide to multi-carbon products on copper nanosheet arrays via cation-catalyst interaction

Electrochemical carbon dioxide reduction offers an efficient way to curtail carbon emissions and generate value-added chemicals and fuels. However, this reaction still suffers from sluggish kinetics and poor selectivity, especially for the formation of multi-carbon products. Here, we report the preparation of copper nanosheet arrays mainly enclosed by {100} facets on copper foils. The copper nanosheets promote the formation of multi-carbon products with a multi-carbon to single-carbon ratio of 7.2, which is almost 18 times that of bare copper foils. Electrochemical investigations reveal that the density of adsorbed potassium ions on copper nanosheet surfaces is approximately five times that on pristine copper foils. Theoretical calculations indicate that the adsorbed potassium ions can effectively modulate the electronic structures of copper nanosheets and thus lower the energy barriers for highly selective generation of multi-carbon products. This work highlights the substantial implications of cation-catalyst interactions for multi-carbon production in electrochemical carbon dioxide reduction reaction.