Catalytic composites of the reaction product of a metal halide having Friedel-Crafts activity with the bound surface hydroxyl group of inorganic oxides and containing a zerovalent metal with hydrogenation activity, often are effective catalysts in motor fuel alkylation which, however, undergo rapid deactivation. Deactivated catalysts are readily regenerable by treating the composite from which alkylate feedstock has been removed with hydrogen at temperatures in the range of 10.degree. to 300.degree. C. Multiple regenerations are possible without appreciable activity loss.