Water oxidation to oxygen by cerium(IV) ions mediated by ruthenium dioxide catalyst

Abstract

Cerium(IV) ions are shown to oxidize water to O₂ in the presence of RuO₂ catalyst in 0.5 mol dm^–3 H₂SO₄ solution. The yield of oxygen depends strongly on the relative concentrations of Ce⁴⁺ and RuO₂. High ratios of Ce⁴⁺ to RuO₂ favour corrosion of the catalyst, a fact which is explained by electrochemical concepts. Our results are discussed in relation to an earlier proposition concerning the mechanism of the water oxidation reaction by Ce⁴⁺ ions in this system.