Abstract: Hydrogen peroxide is produced by a process which uses as catalyst a polymer which has anthraquinone/anthrahydroquinone groups attached to it, and which exhibits differential solubility in water. The polymer is water soluble under one set of conditions, e.g. temperature range, but insoluble under another set of such conditions. Accordingly, the polymer bound anthrahydroquinone groups are oxidized in aqueous solution to form anthraquinone groups and hydrogen peroxide, which dissolves in the aqueous medium. Then the conditions, e.g. temperature, are changed to precipitate the polymer, which can readily be separated off, ready for re-use.