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, Cu^I, 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 1.0mgcm^-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.