Electrochemical Reduction of Carbon Dioxide on Cu/CuO Core/Shell Catalysts

We investigate the electrochemical behavior of different loadings of a Cu(core)/CuO(shell) catalyst in a standard three-electrode cell, which reveals transformations between Cu, CuI, and CuO species. The electroreduction of CO2 on the catalyst is performed in an aqueous solution within a flow reactor. CO and HCOOH are the main products, with H2 as a byproduct. When the catalyst loading is 1.0 mg cm−2, the faradaic efficiencies of CO and HCOOH are higher than those with other catalyst loadings, with a short reaction time. This paper also focuses on the experimental and kinetic details of the electroreduction process of CO2 to CO and HCOOH when using the Cu/CuO catalyst. Reactions are modeled by using an in-series, first-order reaction, and the models are verified to reasonably describe the two products formed during the electroreduction of CO2. According to the kinetic analysis, the rate constant for HCOOH production is higher than that of CO.