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

• Effect of pressure and current on electrochemical conversion of CO 2 to formate. • Use of a relatively large-area Sn cathode (260 cm 2 ) in an undivided cell. • Best performances at intermediate values of pressure and current. • Final formate concentrations up to 5 wt% Recently, the pressurized electrochemical reduction of CO 2 (PrCO 2 RR) in aqueous systems has emerged as a particularly promising route for the conversion of CO 2 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 PrCO 2 RR 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), CO 2 pressure ( P CO 2 , 1–30 bar), supporting electrolyte concentration, and electrolysis duration. The best performances were obtained at intermediate values of both I and P CO 2 , enabling efficient CO 2 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 PrCO 2 RR.