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Adherent electroactive films of poly͑o-phenylenediamine͒ ͑PPD͒ were obtained by electropolymerization of o-phenylenediamine ͑o-PD͒ on 304 stainless steel under potentiostatic conditions. The in situ Fourier transform infrared reflectance spectroscopy study suggests a phenazine ring ladder-structure polymer. Open circuit potential and potentiodynamic studies of PPD-coated steel electrodes, in chloride aqueous solution show a positive shift of the corrosion potential.

Growth of a highly colored insoluble material on a platinum electrode by the oxidative reaction of 1,2-dimethoxybenzene (veratrole) in acetonitrile is observed when tetrabutylammonium tetrafluoroborate is used as supporting electrolyte. The organic yield of the deposit reaches 98% when short-timed electrolyses are performed. The main product has been characterized by several electrochemical and spectroscopic methods.Electrochemical oxidation of methoxybenzenes has been studied since 1964.1 The same year, Eberson 2 and Ross 3 proposed a radical ion as the intermediate species involved. Theoretical models were developed in order to explain the electrochemical behavior of the substrates. 41~ A rule was suggested 14 for the electrochemical reaction of aromatic compounds: side chain substitution would follow a mechanism via free radical, while ring substitution would be explained via a carbonium ion mechanism. Bechgaard and Parker 16 synthesized mono-triphenylene, di-triphenylene, and tri-triphenylene cations from the anodic oxidation of 1,2-dimethoxybenzene in trifluoroacetic acid (TFA). The extraordinary stability of organic cationic radicals in TFA allowed the reaction to be stopped at the radical cation stage, thus enabling the study of the effect of electrochemical variables on it.

The electrooxidation of methanol on an iridium disk in the pH range 0−14 was studied by Fourier transform infrared (FTIR) spectroscopy. The following solutions were used:  1 M H2SO4, 0.1 M HClO4, 1 M H3PO4, and 1 M Na2SO4 whose pH had been adjusted to 2 with H2SO4, 0.5 M phosphate buffer of pH 7, 0.1 M borax buffer, and 1 M NaOH. Linear potential sweep (LPS) FTIR spectroscopy showed that the products of 0.1−1.0 M methanol electrooxidation on smooth Ir were CO2 and formic acid in acidic media and bicarbonate/carbonate and formate ions in alkaline media. Only at pH 7 and 9.2 neither formic acid nor formate ion was detected. The activity of Ir for methanol electrooxidation was very low. At all pH values dissociative chemisorption of methanol yielded chemisorbed CO, always in the linear form. At pH 14 this chemisorbed CO was completely electrooxidized by 0.6 V vs RHE, a value 0.4 V less positive than in perchloric and phosphoric acids of pH 1. This behavior is parallel to that of the appearance of formate/formic:  at pH 14 formate is detected already at 0.4 V, while in perchloric and phosphoric acids of pH 1 formic acid is first detected at 0.9 V. This dependence on pH of the electrocatalytic activity of Ir both for the electrooxidation of chemisorbed CO and for that of methanol to formate/formic is in perfect agreement with the fact that the peak of the main Ir surface oxidation process occurs at 0.6 V vs RHE at pH 14, but at a rather more positive potential, 0.9−1.0 V vs RHE, in acidic media (super-Nernstian pH dependence). This agreement lends support to the hypothesis that the electrooxidation of organic compounds requires the presence of oxide, hydroxide, and/or oxyhydroxide groups on the Ir surface, which provide the O atoms necessary for the formation of CO2 and formic/formate. However, in sulfuric acid, both at pH 0 and 2, formic acid was already observed at 0.7 V, possibly because in sulfuric acid a prepeak of Ir oxidation at 0.6 V that precedes the main peak at 1.0 V is better defined. The stretching frequency of linear CO increased by up to 60 cm-1 with increasing coverage and at the same coverage was higher in HClO4 than in H3PO4 solutions. The Stark shift varied over the range 39−45 cm-1 V-1 with pH, CO coverage, and nature of the anion in the case of acids.