Understanding the impact of reaction parameters on electrochemical reduction of CO2 to methanol: Activity relationship of cuprite@polyaniline electrodes

The carbon dioxide reduction reaction (CO₂RR) is a key reaction that efficiently uses CO₂ to produce value-added chemicals. However, the main limitation of this reaction is its low selectivity which results in the formation of a variety of by-products. As a result, the current challenge for CO₂RR is the efficient formation of product with high Faradaic efficiency (FE). Our main goal is to replace precious metal electrocatalysts with more abundant transition metal/conducting support hybrid catalysts. Herein, we’ve synthesized a cuprite-polyaniline (Cu₂O@PANI) composites. The superior catalytic activity in terms of activity and selectivity for methanol (MeOH) synthesis could be attributed to the synergism between Cu₂O and PANI that enables it to scale back multiple species, higher electrical conductivity, and lowest resistance during the charge/mass transfer processes. These properties were confirmed using Electrochemical impedance spectroscopy (EIS), Electron transfer rate constant (Ks), Mott-Schottky (MS), Double-layer capacitance (DLC), and Density-functional theory (DFT) analysis. Based on these findings Cu₂O@PANI matrix easily forms many intermediate (CO) species and maintains a higher CO₂ concentration around the electrode surface throughout the experiment. The results of the given electrocatalytic system show that the Cu₂O@PANI matrix significantly suppressed the by-product throughout the experiment, resulting in MeOH (45.21%) FE within 90 min. Given these benefits, the catalytic system is appropriate for CO₂RR.