Fig. 1. Schematics showing morphology of Cu catalysts.
a The method used to prepare Cu catalysts for electrochemical CO2RR: anodic halogenation in KX solutions where X = halogen, oxide formation in basic KHCO3, and electroreduction in neutral KHCO3 by LSV. EP-Cu corresponds to electropolished Cu foils, LSV corresponds to linear sweep voltammetry. b Two-dimensional visualization of under-coordinated Cu atoms and surface roughness with the corresponding outcomes when used for the electrochemical CO2RR. This schematic is simplified but face-centered cubic Cu has a coordination number of 12.