Pressurized CO2 electrochemical conversion into formate using an undivided cell equipped with large-area Sn electrodes

Recently, the pressurized electrochemical reduction of CO2 (PrCO2RR) in aqueous systems has emerged as a particularly promising route for the conversion of CO2 into value-added products. To facilitate the development of this process at an applicative scale, it is essential to evaluate its performance at appreciable current intensities (I) using systems that are low-cost and easily scalable. In this work, the PrCO2RR to formate (FA) was carried out in a simple undivided cell equipped with relatively large-area Sn cathode, investigating the effects of several key parameters, including I (4-20 A), CO2 pressure (PCO2, 1-30 bar), supporting electrolyte concentration, and electrolysis duration. The best performances were obtained at intermediate values of both I and PCO2, enabling efficient CO2 conversion to FA with high productivity and final formate concentrations up to 5 wt%, which are significantly higher than those previously reported in the literature for PrCO2RR.