A hydrocarbon conversion process which utilizes a novel catalytic composite is disclosed. The catalyst composite comprises a platinum group metal component, a first modifier selected from Group IA and IIA elements of the Periodic Table, a second modifier component selected from the group of elements consisting of palladium, iridium, and osmium, and a third modifier component selected from the elements of Group IVA of the Periodic Table of the Elements. All of the catalytic components are located on a refractory oxide support having a nominal diameter (d) of from 50 to 10,000 microns. The catalytic composite is characterized in that the second modifier components is surface-impregnated upon the support in such a manner that the average concentration of the surface-impregnated second modifier component on the outside 0.2d micron catalyst layer is at least 2 times the average concentration of the second modifier component in 0.4d micron diameter center core of the catalyst where d is the nominal diameter, and wherein the first modifier metal component is uniformly impregnated. The process has been found to be most useful in the dehydrogenation of dehydrogenatable hydrocarbons.