| abstract |
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 palladium, silver and rhenium on a carbon support and is prepared by the steps of n (i) impregnating a carbon support with a source of palladium, silver and rhenium, wherein the source of palladium, silver and rhenium is at least one solution, n (ii) after each impregnation step, drying the impregnated carbon support to remove solvent, n (iii) heating the impregnated carbon support at a temperature of about 120° C. to about 350° C. under reducing conditions. n The palladium in the catalyst is present in the form of crystallites having a particle size of less than 10 nm. |