highly active , acidic sulfactive metal hydrogenation catalysts comprising mo and / or w plus ni and / or co are prepared by methods comprising as the essential novel feature impregnating gamma alumina particles with an aqueous solution having dissolved therein one or more fluosilicates of cobalt and / or nickel , followed by drying and calcining . the resulting compositions contain uniformly distributed fluorine and sio 2 as active acidic promoters , intimately associated with the sulfactive metal components .