ELECTROCHEMICAL-BEHAVIOR OF THE ADSORBED IMIDAZOLIUM FILM ON PLATINUM

An adsorbed layer is formed during the electrochemical reduction of pr otonated imidazole in acetonitrile on Pt surface. The film is stable a t ambient conditions and the IR spectrum gives an evidence that it pro bably has polymeric structure. Elucidation of the cyclic voltammograms of the film led to the proposal that the film prevents the molecular hydrogen evolution and thus stabilizes the adsorbed hydrogen on the su rface. Adsorbed hydrogen could be reintroduced after all the hydrogen is stripped off the film by the electroreduction of protons in dilute acid solution in acetonitrile. The electrooxidation of chloride ions a nd electroreduction of molecular oxygen on the film coated surface pro vided further evidence for the proposed mechanism.