FTIR-Assisted Electroreduction of CO₂ and H₂O to CO and H₂ by Electrochemically Deposited Copper on Oxidized Graphite...

Obtaining CO and H₂ from electrochemical CO₂ reduction (CO₂RR) offers a viable alternative to reduce CO₂ emissions and produce chemicals and fuels. Herein, we report a simple strategy for obtaining polycrystalline copper deposited on oxidized graphite felt (Cu-OGF) and its performance on the selective conversion of CO₂ and H₂O to CO and H₂. For the electrode obtaining, graphite felt (GF) was first oxidized (OGF) in order to make the substrate hydrophilic and then copper particles were electrochemically deposited onto OGF. The pH of deposition was investigated, and the CO₂RR activity was assessed for the prepared electrodes at each pH (2.0, 4.0, 6.0, 8.0, and 10.0). It was found that pH 2.0 was the most promising for CO₂RR due to the presence of hexagonal copper microparticles. Fourier transform infrared analysis of the produced gases showed that this is a low-cost catalyst capable of reducing CO₂ and H₂O to CO and H₂, with Faradaic efficiencies between 0.50 and 5.21% for CO and 50.87 to 98.30% for H₂, depending on the experimental conditions. Hence, it is possible for this gas mixture to be used as a fuel gas or to be enriched with CO for use in Fischer-Tropsch processes.