abstract |
A novel catalytic composite comprising a platinum group metal component; a modifier metal component selected from the group consisting of a tin component, germanium component, rhenium component and mixtures thereof; an alkali or alkaline earth metal component or mixtures thereof, an optional halogen component, and an optional catalytic modifier component on a refractory oxide support having a nominal diameter of at least about 850 microns. The distribution of the platinum group metal component is such that the platinum group component is surface-impregnated where substantially all of the platinum group metal component is located at most within a 400 micron exterior layer of the support. The effective amount of the modifier metal component may be uniformly impregnated throughout the refractory oxide support, surface-impregnated, or located in any other appropriate fashion. The distribution of the surface-impregnated modifier metal component is such that the modifier metal component is substantially all located at most within a 400 micron exterior layer of the support. The novel catalyst has particular utility as a hydrocarbon dehydrogenation catalyst. A method of preparing the catalyst is also disclosed. |