BaO2

BaO2, or barium peroxide, is an inorganic compound that forms the peroxide salt of barium. It is a white to pale yellow crystalline solid consisting of Ba2+ cations and the peroxide anion (O2^2−).

At room temperature it is relatively stable, but it is reactive with water and acids, and it thermally decomposes upon heating to give barium oxide and oxygen gas: 2 BaO2 → 2 BaO + O2.

Preparation of BaO2 can be achieved by the direct oxidation of BaO with oxygen at elevated temperatures, or by methods that convert other barium salts to the peroxide form.

Reactions of BaO2 include its interaction with water to form barium hydroxide and hydrogen peroxide: BaO2 + 2 H2O → Ba(OH)2 + H2O2. Hydrogen peroxide can subsequently decompose to water and oxygen. With acids, the peroxide can release oxygen through the decomposition of the formed hydrogen peroxide; in general, BaO2 behaves as an oxidizer and can contribute to oxygen generation in situ.

Applications of BaO2 have included use as an oxidizing agent in laboratory synthesis and as a solid oxygen source in chemical oxygen generators. It has also been studied in materials chemistry for potential oxygen storage capabilities.

Safety considerations are important: BaO2 is a strong oxidizer and can pose fire and explosion hazards, especially in contact with organic materials or reducing agents. It is moisture sensitive and can form caustic barium hydroxide on contact with water. Handle under dry conditions and store away from acids and reducing substances.