Collect. Czech. Chem. Commun. 1995, 60, 795-801

New Procedure for Linear Sweep Voltammetric Determination of Catalytic Reaction Rate Constant. Oxidation of Some Aliphatic Alcohols with Electrolytically Generated Os(VIII)

Dušan Bustin, Štefan Mesároš, Peter Tomčík and Miroslav Rievaj

Department of Analytical Chemistry, Slovak Technical University, 812 37 Bratislava, Slovak Republic


Oxidation rate of methanol, ethanol and 2-propanol by Os(VIII) in 1 M KOH was determined by evaluating anodic voltammograms of Os(VI) in the presence of the aliphatic alcohols. The proposed method is based on the evaluation of the change of voltammogram shape by catalytic process and on the assumption of its approximation by fractionally integrated voltammograms. This assumption has been confirmed empirically for k'f /a in the interval of <0.04,1>. The rate constants from this interval could be determined with sufficient accuracy. The method is suitable for evaluation of reaction rates slow and moderately fast catalytic reactions. It was compared with other evaluation methods from the literature.