Investigation of adsorption phenomena on platinized platinum electrodes by tracer methods simultaneous study of the oxidation and adsorption of oxalic acid

Abstract

The role of adsorbed species in the oxidation of oxalic acid was studied by the simultaneous application of tracer techniques and electrochemical methods. It has been established that there is a difference between results at preoxidized and non-oxidized surfaces. In the former case the extent of the adsorption is very small, nevertheless the reaction proceeds at a significant rate. In the latter case an unambiguous relation between adsorptive coverage and reaction rate was obtained. It has been shown that the contradiction may be resolved by supposing that the number of active sites taking part in the reaction is a negligible part of all surface sites. The fundamental role of adsorption in the reaction has been shown by considering the simultanous effect of Cl − ions on the reaction rate and on the adsorption of oxalic acid. Data obtained from polarization measurements differ from those given in the literature.