The Haber-Weiss cycle consists of the following two reactions :
H2O2 + OH. 
H2O + O2- + H+ and H2O2 + O2- O2 + OH- + OH.
The second reaction achieved notoriety as a possible source of hydroxyl radicals. However, it has a negligible rate constant. It is believed that iron(III) complexes can catalyze this reaction: first Fe(III) is reduced by superoxide, followed by oxidation by dihydrogenperoxide. See also Fenton reaction.
