A working solution comprising anthraquinone and its derivatives, used for the production of hydrogen peroxide on becoming degraded by formation of non-effective anthraquinone is generated by an auto-oxidation process employing anthraquinone, which comprises:Contacting, at a temperature of below 130.degree.C., and in the presence of a catalyst comprising a metal selected from a platinum group and supported on a carrier, said degraded working solution, which comprises non-effective anthraquinone and tetrahydroanthraquinone with an olefinic compound whose hydrogenation product is gaseous at said contact temperature andSubsequently, contacting the thus treated working solution, at a temperature above 130.degree.C., and in the presence of a catalyst comprising a metal selected from the platinum group and supported on a carrier, with an olefinic compound whose hydrogenation product is gaseous at said contact temperature,Said method being characterized by the fact that at a temperature below 130.degree.C., the regeneration of non-effective anthraquinone is accelerated much faster than the dehydrogenation reaction of tetrahydroquinone and therefore, at a pont in time, when all non-effective anthraquinone has been converted to anthraquinone, the temperature can be raised above 130.degree.C. to permit dehydrogenation of said tetrahydroanthraquinone without incurring any impedance of the dehydrogenation reaction.