Electrochemical conversion of pressurized CO2 at simple silver-based cathodes in undivided cells: study of the effect of pressure and other operative parameters

Electrochemical reduction of pressurized CO2 is proposed as an interesting approach to overcome the main hurdle of the CO2 electrochemical conversion in aqueous solution, its low solubility (ca. 0.033 M), and to achieve good faradaic efficiency in CO using simple sheet silver cathodes and undivided cells, thus lowering the overall costs of the process. The effect on the process of CO2 pressure (1–30 bar), current density, nature of the supporting electrolyte and other operative conditions, such as the surface of the cathode or the mixing rate, was studied to enhance the production of CO. It was shown that pressurized conditions allow to improve drastically the current efficiency of CO (CECO). Furthermore, at relatively high pressure (20 bars), the utilization of simple sheet silver cathodes and silver electrodes with high surfaces gave similar CECO. The stability of the system was monitored for 10 h; it was shown that at a relatively high pressure (15 bar) in aqueous electrolyte of KOH using a simple plate silver cathode a constant current efficiency of CO close to 70% was obtained. Graphic abstract

Cathodic electrochemical deposition: a new strategy to enhance the activity and stability of silver cathodes for thin-film solid oxide fuel cells

Cathodic electrochemical deposition-treated silver cathodes for solid oxide fuel cell achieved 40% enhanced peak power density and 50 hour thermal stability.

Electrocatalytic Processes for the Valorization of CO2: Synthesis of Cyanobenzoic Acid Using Eco-Friendly Strategies

Carbon dioxide (CO2) is a known greenhouse gas, and is the most important contributor to global warming. Therefore, one of the main challenges is to either eliminate or reuse it through the synthesis of value-added products, such as carboxylated derivatives. One of the most promising approaches for activating, capturing, and valorizing CO2 is the use of electrochemical techniques. In the current manuscript, we described an electrocarboxylation route for synthesizing 4-cyanobenzoic acid by valorizing CO2 through the synergistic use of electrochemical techniques (“green technology”) and ionic liquids (ILs) (“green solvents”)—two of the major entries in the general green chemistry tool kit. Moreover, the use of silver cathodes and ILs enabled the electrochemical potential applied to be reduced by more than 0.4 V. The “green” synthesis of those derivatives would provide a suitable environmentally friendly process for the design of plasticizers based on phthalate derivatives.