Tuning the selectivity of Cu2O/ZnO catalyst for CO2 electrochemical reduction

Different post-synthesis procedures were employed for enhancing the performance of a Cu2O/ZnO catalyst to the electrochemical reduction of CO2 (ERCO2). In general, the explored procedures successfully controlled critical physicochemical parameters that govern the catalytic behavior, such as the oxidation state, number of oxygen defects, crystallite size, and the strength of the copper-zinc interaction. In particular, it was shown that it is possible to tune the H2/CO production ratio (syngas composition) by applying in situ potential cycling treatments immediately before the electrochemical measurements, under the reaction conditions. For an applied potential of − 1.0 VRHE, an H2/CO ratio value of 2.5, 5, and 0.7 was obtained using the same catalyst when subjected to different post-synthesis procedures.