Catalysts for the hydrogenation of aqueous maleic acid to 1,4-butanediol

摘要

Maleic acid, maleic anhydride or other hydrogenatable precursor are catalytically hydrogenated to 1,4-butanediol and tetrahydrofuran. It has been discovered that high yields of 1,4-butanediol are achieved when the hydrogenation catalyst comprises at least one noble metal of Group VIII of the Periodic Table and at least one of rhenium, tungsten or molybdenum on a carbon support wherein the carbon support has been contacted with an oxidizing agent prior to the deposition of the metals. This hydrogenation catalyst is prepared by the steps of (i) oxidizing the carbon support by contacting the carbon support with an oxidizing agent, (ii) impregnating in one or more impregnation steps comprising contacting the carbon support with a source of Group VIII metal and at least one metal selected from the group consisting of rhenium, tungsten and molybdenum being in at least one solution, (iii) after each impregnation step, drying at a temperature under about 150 DEG C. the impregnated carbon support to remove solvent, (iv) heating the impregnated carbon support at a temperature of about 100 DEG C. to about 350 DEG C. under reducing conditions.