Hydrogen Peroxide (H2O2)

Hydrogen Peroxide

Hydrogen peroxide has the chemical formula H2O2 and is a strong oxidizer. The molar mass is 34.0147 g/mol. Hydrogen peroxide is commercially available in concentration from 3% (household use) to 60% for some industrial uses. In water treatment applications 30-50% concentrations are most common. Hydrogen peroxide is manufactured today almost exclusively by the autoxidation of 2-ethyl-9,10-dihydroxyanthracene (C16H14O2) to 2-ethylanthraquinone (C16H12O2) and hydrogen peroxide using oxygen from the air.

It has a wide variety of industrial application. One of the main uses of hydrogen peroxide for pulp- and paper-bleaching. Other bleaching applications are becoming more important as hydrogen peroxide is seen as an environmentally benign alternative to chlorine-based bleaches.

Other major industrial applications for hydrogen peroxide include the manufacture of sodium percarbonate and sodium perborate, used as mild bleaches in laundry detergents. Hydrogen peroxide is also used in the production of epoxides such as propylene oxide. Reaction with carboxylic acids produces a corresponding peroxy acid. In the PCB manufacturing process, hydrogen peroxide mixed with sulfuric acid was used as the micro etch chemical for copper surface roughening preparation.

It can be used alone or with catalysts to oxidize organic and inorganic compounds in water. In advanced oxidation processes hydrogen peroxide is combined with UV radiation , certain metal compounds (most notably iron (Fe)) or ozone to form hydroxyl radicals. With respect to metal catalysts, such as Fe2+ or Ti3+, the decomposition may take a different path, with free radicals such as HO· (hydroxyl) and HOO· being formed. A combination of H2O2 and Fe2+ is known as Fenton’s reagent.