Multi‐Shell Copper Catalysts for Selective Electroreduction of CO2 to Multicarbon Chemicals.

Electrocatalytic CO2 reduction (CO2R) coupled with renewable electricity has been considered as a promising route for the sustainability transition of energy and chemical industries. However, the unsatisfactory yield of desired products, particularly multicarbon (C2+) products, has hindered the implementation of this technology. This work describes a strategy to enhance the yield of C2+ product formation in CO2R by utilizing spatial confinement effects. The finite element simulation results suggest that increasing the number of shells in the catalyst wil lead to a high local concentration of *CO and promotes the formation of C2+ products. Inspired by this, Cu nanoparticles are synthesized with desired hollow multi‐shell structures. The CO2 reduction results confirm that as the number of shells increase, the hollow multi‐shell copper catalysts exhibit improved selectivity toward C2+ products. Specifically, the Cu catalyst with 4.4‐shell achieved a high selectivity of over 80% toward C2+ at a current density of 900 mA cm−2. Evidence from in situ attenuated total reflection surface‐enhanced infrared absorption spectroscopy unveils that the multi‐shell Cu catalyst exhibits an enhanced *COatop coverage and the stronger interaction with *COatop compared to commercial Cu, confirming the simulation results. Overall, the work promises an effective approach for boosting CO2R selectivity toward value‐added chemicals. [ABSTRACT FROM AUTHOR]