Hydrogen evolution in the presence of CO₂ in an aqueous solution during electrochemical reduction

This study investigated the electroanalytic behaviors of different Cu(core)/CuO(shell) catalyst loadings in a standard three-electrode cell in an aqueous solution. Transformations between Cu, Cu(I), and CuO as a function of applied potential were observed. Electrochemical reduction in the presence of CO₂ was conducted in a flow reactor. Hydrogen evolution occurred during electrochemical reaction. The H₂ Faradaic efficiency was between 40% and 65%. Differential equations were used to model the hydrogen evolution reaction. The models were able to describe the electrochemical reduction that occurred. According to kinetic analysis, the H₂ rate constant was not affected by increased catalyst loadings.