Barium peroxide Being an oxidizer and giving a vivid green colour upon ignition (as do all barium compounds), it finds some use in fireworks; historically, it was also used as a precursor for hydrogen peroxide.
Barium peroxide used in the preparation of barium salt or hydrogen peroxide, as an oxidant, bleach, mordant, disinfectant, etc. It is also useful in fireworks because it burns with a dazzling green light.
Barium peroxide arises by the reversible reaction of O2 with barium oxide. The peroxide forms around 500 °C and oxygen is released above 820 °C.
2 BaO + O2 ⇌ 2 BaO2
This reaction is the basis for the now-obsolete Brin process for separating oxygen from the atmosphere. Other oxides, e.g. Na2O and SrO, behave similarly.
In another obsolete application, barium peroxide was once used to produce hydrogen peroxide via its reaction with sulfuric acid:
BaO2 + H2SO4 → H2O2 + BaSO4
The insoluble barium sulfate is filtered from the mixture.