Preanodized Cu Surface for Selective CO<sub>2</sub> Electroreduction to C<sub>1</sub> or C<sub>2+</sub> Products
Chang Liu, Jun Gong, Jinmeng Li, Jinlong Yin, Wenzheng Li, Zeyu Gao, Li Xiao, Gongwei Wang, Juntao Lu, Lin Zhuang
Abstract
The electrochemical CO2 reduction over Cu catalysts has shown great potential in producing a wide range of valuable chemicals, but it is still plagued by a poor controllability on product distribution. Herein, we demonstrate an effective regulation of CO2 reduction paths through a preanodization treatment of Cu foil electrodes in different electrolytes. The Cu electrode exhibits a superior C1 and C2+ product selectivity after being preanodized in NaClO4 (Cu-NaClO4) and Na2HPO4 electrolyte (Cu-Na2HPO4), respectively. Combined with in situ electrochemical Raman, ATR-SEIRAS, and SEM characterizations, the preferential C1 path is due to the deposition of many Cu nanocrystals with dominant Cu(111) facets on the Cu-NaClO4 electrode. In contrast, the preferential C2+ path over the Cu-Na2HPO4 is attributed to formation of a unique Cu nanodendritic morphology, which strengthens the *CO intermediate adsorption and induces an environment of low local H2O/CO2 stoichiometric ratio, thus facilitating C–C coupling for C2+ production. Our findings may shed light on the rational control of the CO2 reduction path through engineering of the Cu surface structure.