Researchers from the Interface Science Department (ISC) of the Fritz Haber Institute and the University of California Los Angeles (UCLA) have provided insight into the significant morphological changes that Cu surfaces undergo during the electrochemical reduction of CO2, which influences the type of products formed. This combined theory (UCLA)-experimental ISC-FHI) study highlights the importance of specific surface defects, that are created and transformed in the course of the reaction, for enhancing the efficiency of CO2 conversion into industrially valuable chemicals.