The anodic behaviour of Ebonex® in oxalic acid solutions

A study of the oxidation of aqueous solutions of oxalic acid in various supporting electrolytes, at an Ebonex^® anode is reported. From data obtained by cyclic voltammetry, linear sweep voltammetry, chronopotentiometry, controlled potential coulometry and gas chramatography it has been shown that oxalic acid oxidation at an Ebonex^® anode, does not proceed, to any significant extent. Data collected using different electrolytes showed that sulphuric acid supported higher current densities at similar electrode potentials. Ebonex^® is essentially a selective oxygen evolver and is thus a suitable anode for the electroreduction of oxalic acid to glyoxylic acid in an undivided cell. The behaviour of a platinized titanium anode is also reported and this material has similar electrochemical characteristics to Ebonex^® in aqueous oxalic acid solutions.