The invention relates to a method of regenerating hydrogenated and/or oxygenated alkyl anthraquinones and/or alkyl anthrahydroquinones to alkyl anthraquinones and/or alkyl anthrahydroquinones, wherein the reaction is carried out in the presence of a catalyst under electromagnetic irradiation. Additionally the invention relates to a method for regenerating a working solution containing hydrogenation and/or oxidation products of alkyl anthraquinones and/or alkyl anthrahydroquinones dissolved in at least one solvent, wherein said working solution contains alkyl anthraquinone and/or alkyl anthrahydroquinone products being formed during the production of hydrogen peroxide by a cyclic process including alternate reduction and oxidation of the working solution, said method comprising contacting the working solution containing hydrogenation and/or oxidation products of alkyl anthraquinones and/or alkyl anthrahydroquinones with a catalyst under electromagnetic irradiation to convert the hydrogeneration and/or oxidation products of alkyl anthraquinones and/or alkyl anthrahydroquinones to productive alkyl anthraquinones and/or alkyl anthrahydroquinones.