The effects of differing degrees of thermal activation of RuO2·xH2O on its corrodability and oxygen catalytic activity

Abstract

The kinetics of dissolution and oxygen catalysis of RuO₂·xH₂O samples, thermally activated at different temperatures in the range ambient to 100°C, are reported. The results of a kinetic study show that increasing the temperature of activation causes an increasingly thick, dissolution-inert and diffuse layer to form on the outside of the particles. The observed decrease in activity towards dissolution with increased annealing temperature is mirrored an by increase in the activity of the samples as catalysts for the oxidation of water to O₂ by the BrO⁻₃ ions present. The results of this work re-enforce the crucial link between the water content of a hydrated sample of ruthenium dioxide and its activity as an oxygen catalyst.