Enhanced electrochemical CO2-to-C2+ conversion from synergistic interaction between terrace and step sites on monocrystalline high-index Cu facets

The synergistic interaction between terraces and step sites plays a key role to enhance the production of C 2+ fuels from electrochemical CO 2 reduction. • Ten large-area monocrystalline Cu foils exposing high-index facets were designed and fabricated. • The strong synergistic interaction between terrace and step plays a key role for C 2+ production. • The geometric balance between terrace and step is crucial to promote CO* –CHO* dimerization.