Bifunctional Cu-Based Catalyst for Electrochemical Conversion of Carbon Dioxide into CO and Formate

Abstract

Electrocatalytic conversion of CO2 into value-added products is increasingly becoming one of the most viable approaches for mitigating the negative impacts of anthropogenic CO2 emissions and alleviating the impact of these emissions on global warming. However, the effectiveness of the electrocatalytic conversion technique is highly dependent on the type of electrocatalyst used and at times limited by the selectivity of the catalyst towards one specific product. In this work, CuO nanocatalysts were synthesized using sol-gel technique and applied for the electrochemical conversion of carbon dioxide into CO and formate. The synthesized catalysts were characterized using X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), Transmission electron microscopy (TEM), and X-ray powder diffraction (XRD) techniques. A homogenous mixture of the synthesized nanocatalysts with PTFE was uniformly deposited on carbon electrode through the drop-casting technique. The electrochemical activity of the prepared electrodes was then investigated using Linear sweep voltammetry, cyclic voltammetry, and chronopotentiometry techniques. The results indicated that electrodes prepared using the synthesized CuO catalyst can be effectively applied to convert carbon dioxide into both CO and formate at different current densities. At a high current density of 50 mA.cm-2, the CuO-doped carbon electrodes could simultaneously produce 470 ppm of CO and 273 ppm of formate. Furthermore, the CuO nanocatalyst doping exhibited high stability on the carbon electrodes, which indicates that the electrodes can be effectively applied for large-scale applications.