METHOD OF PREPARING ALKALI-METAL PEROXIDE SOLUTIONS

摘要

Described is a method of preparing an aqueous alkali-metal peroxide solution in which the molar ratio of alkali metal to H2O2 lies between 0.5 and 2.5 in an electrochemical cell consisting of a porous oxygen diffusion cathode, a cation-exchange membrane and an anode, an electrolyte containing sulphuric acid flowing through the anode chamber, an electrolyte containing an alkali-metal hydroxide flowing through the cathode chamber, and alkali-metal peroxide being formed by cathodic reduction of oxygen. In this method, alkali-metal hydrogen sulphate is included in one electrolyte circuit, the starting material for this alkali-metal hydrogen sulphate being an aqueous solution of alkali-metal sulphate or hydrogen sulphate or a mixture of alkali-metal sulphate and hydrogen sulphate or an aqueous solution of alkali-metal sulphite or hydrogen sulphite or a mixture of alkali-metal sulphite and hydrogen sulphite or an aqueous solution of alkali-metal carbonate or hydrogen carbonate or a mixture of alkali-metal carbonate and hydrogen carbonate, an aqueous solution of sulphuric acid or pure, gaseous sulphur dioxide or pure, gaseous carbon dioxide being produced.