Abstract
Electrochemical CO2 reduction to valuable ethylene and ethanol offers a promising strategy to lower CO2 emissions while storing renewable electricity. Cu-based catalysts have shown the potential for CO2-to-ethylene/ethanol conversion, but still suffer from low activity and selectivity. Herein, the effects of surface and interface structures in Cu-based catalysts for CO2-to-ethylene/ethanol production are systematically discussed. Both reactions involve three crucial steps: formation of CO intermediate, C-C coupling, and hydrodeoxygenation of C-2 intermediates. For ethylene, the key step is C-C coupling, which can be enhanced by tailoring the surface structures of catalyst such as step sites on facets, Cu-0/Cu delta+ species and nanopores, as well as the optimized molecule-catalyst and electrolyte-catalyst interfaces further promoting the higher ethylene production. While the controllable hydrodeoxygenation of C-2 intermediate is important for ethanol, which can be achieved by tuning the stability of oxygenate intermediates through the metallic cluster induced special atomic configuration and bimetallic synergy induced the double active sites on catalyst surface. Additionally, constraining CO coverage by the complex-catalyst interface and stabilizing C-O bond by N-doped carbon/Cu interface can also enhance the ethanol selectivity. The structure-performance relationships will provide the guidance for the design of Cu-based catalysts for highly efficient reduction of CO2.