The Haber–Weiss cycle consists of the following two reactions:
H2O2 + OH·H2O + O2− + H+
H2O2 + O2−O2 + OH− + OH·The second reaction achieved notoriety as a possible source of hydroxyl radicals. However, it has a negligible @O04322@. It is believed that iron(III) complexes can catalyse this reaction: first, Fe(III) is reduced by superoxide, followed by @O04362@ by dihydrogen peroxide.