hydrogen peroxide

hydrogen peroxide, the common name for hydrogen peroxide aqueous solution (colorless, odorless, transparent), as a strong oxidant and disinfectant is widely used in sterilization, sewage treatment, dyeing, bleaching and other fields [1]; the usage concentration is usually between 3% ~30% (mass fraction), it can quickly decompose to produce oxygen at lower concentrations; among them, the commonly used concentration for medical disinfection is 3% ~ 5%. The higher the concentration, the stronger the oxidizing property.

According to the "Catalogue of Hazardous Chemicals (2015 Edition)", hydrogen peroxide with a concentration above 8% is a hazardous chemical (explosive) and is subject to control, and must be stored and used with caution.

At present, the industrial production method of hydrogen peroxide is mainly the anthraquinone method. In addition, there are electrolysis method, Isopropanol oxidation method, oxygen cathode electrolytic reduction method, and direct hydrogen and oxygen synthesis method.

Medical disinfection

In view of the fact that hydrogen peroxide is less irritating (compared to alcohol), highly efficient, quick-acting, and non-toxic, a 3% concentration hydrogen peroxide solution can be used as an oxidizing disinfectant. When it encounters organic matter, it can be decomposed under the action of catalase to produce it. Oxygen, thus playing the role of sterilization, deodorization, decontamination, and hemostasis. It can also destroy the anaerobic environment where tetanus bacilli breed, thereby preventing the occurrence of tetanus symptoms. It can also be used for anti-inflammation or cleaning of otitis externa, tonsillitis, emergency trauma debridement, etc.

Dyeing and bleaching

Hydrogen peroxide, which has bleaching properties (oxidation mechanism), can be used as a bleaching agent, for example, in the renovation of some long-standing furniture. The pigments of some paints contain basic lead carbonate, with a molecular formula of 2PbCO3×Pb(OH)2. When exposed to the air for a long time, it will chemically react with the hydrogen sulfide (H 2 S) in it, resulting in a black precipitate of lead sulfide (PbS). Attached to the surface of furniture, it presents a dull visual effect.

If scrubbed with a certain concentration of hydrogen peroxide, the furniture can be restored to its original color. The principle is that sulfur in the -2 valence state has strong reducing properties and can undergo an oxidation-reduction reaction with H2O2 to remove sulfide precipitation.

4H₂O₂  + PbS → PbSO₄+ 4H₂O

Oxygen production

Thanks to the easy decomposition (unstable) nature of hydrogen peroxide, oxygen can be produced in the laboratory by adding a manganese dioxide (MnO₂ ) catalyst to the hydrogen peroxide solution. Among them, oxygen is difficult to dissolve in water and is denser than air. It can be collected by drainage gas collection method or upward air exhaust method.

industrial production

There are many industrial production methods of hydrogen peroxide, such as electrolytic ammonium persulfate ((NH₄)₂S₂O₈ ) method, Isopropanol (CH₃ -CH-OH-CH₃ ) oxidation method, oxygen cathode electrolytic reduction method, hydrogen The direct oxygen synthesis method, as well as the anthraquinone method that is currently the most widely used, account for more than 90% of global production, and the domestic production even reaches 98%.

The hydrogen peroxide production process includes reaction processes such as hydrogenation of anthraquinone and oxidation of anthraquinone, as well as separation processes such as separation of hydrogen peroxide through pure water extraction.