Catalyst for the selective hydrogenation of polyunsaturated organics

A process for the selective hydrogenation of polyunsaturated organic compounds to monoolefinic organic compounds comprising contacting a feed comprising at least one organic compound selected from the group consisting of dienes, polyenes, alKynes, and triple bonded nitriles in a reaction zone at selective hydrogenation conditions with a catalyst consisting essentially of an alumina support material, about 0.05 to 1.5 wt. % sulfur, and about 1.0 to 25.0 wt. % nickel, where the alumina support material is characterized by having a total pore volume greater than 1.4 but less than 2.5 cc/g, a surface area greater than 150 m.sup.2 /g, with less than 25 percent of the total pore volume being provided by pores having pore diameters of less than 150 angstroms and with over 60 percent of the pore volume being provided by pores having pore diameters greater than 600 angstroms to produce a product substantially free of polyunsaturated organic compounds.