Propanol oxidation on the Pt/RuO2 electrodes in alkaline solutions

Abstract

The propanol oxidation has been studied on catalysts Pt/RuO₂. The electrocatalysts on titanium substrate was formed in the form of thin coating by thermal procedure. The catalytic activity has been revealed through the recording the cyclic voltammograms and polarization and chronocemperometric curves of the oxidation of 1- and 2-propanol in an alkaline anvironment. The rate of propanol oxidation on Pt/RuO₂ is strongly enhanced. A catalysts with a RuO₂ concentration from 40 mol% to 80 mol% RuO₂ were found to be the most active surface for propanol oxidation. Such systems form the so-colled bifunctional catalysts, where Pt facilitates fast adsorption and dehydrogenation. Ru forms oxigencontaing species at lower (0,5V) potentials than Pt. These species are effective in the oxidation of strongly adsorbed intermediaries. The activity of Pt/RuO₂ electrodes toward the electrooxidation of propanol is a balance of the primarily concentration-dependent rate of the dissociative chemisorption of propanol and the potential dependent oxidation rate of intermediaries accumulated on the surface during sustained propanol oxidation.