Preparation

Preparing Hydrogen Peroxide

1. From barium peroxide. Acidifying barium peroxide octahydrate with sulphuric acid, then removing excess water by evaporation under reduced pressure, gives hydrogen peroxide:

2. Via peroxodisulphate. Electrolytic oxidation of acidified sulphate solutions at high current density gives peroxodisulphuric acid, which is then hydrolysed to release hydrogen peroxide:

This same route, run with $D_2O$, is now the standard laboratory preparation of deuterium peroxide, $D_2O_2$:

3. Industrial route — auto-oxidation of 2-alkylanthraquinols. This is the process used at scale:

$\text{2-ethylanthraquinol} \xrightarrow{O_2(\text{air})/H_2,\ Pd} H_2O_2 + \text{(oxidised product)}$ …