Peroxocarbonate production by using a divided cylindrical electrochemical reactor

Abstract

The production of peroxocarbonate was studied in a cylindrical electrochemical reactor divided by a cationic exchange membrane. The anode was a platinum helical wire and the cathodic reaction was either oxygen reduction by using a rotating reticulated vitreous carbon or hydrogen evolution at nickel or platinised titanium static electrodes. Fundamental studies performed with a rotating disc electrode or a rotating ring-disc electrode are reported which orientate the adoption of the operating conditions for the cylindrical reactor. The best results were obtained using a 1 mol/dm3 Na2CO3 solution in the anodic compartment at a current density of 140 mA/cm2 and 10 °C of temperature. The maximum sodium peroxocarbonate concentration was 64.7 mmol/dm3 with a current efficiency of 19.2%. The space time yield was 5.4 kg/m3/h and 11.1 kW h/kg the specific energy consumption. The process performance is similar with both cathodic reactions. The reactor showed a promising behaviour for the electrosynthesis of this oxidising agent.