IMPREGNATING A NOBLE METAL ON THE SURFACE OF A REFRACTORY CATALYST SUPPORT

摘要

Platinum or other platinum-group metals can be deposited substantially on the surface only of pellets of a refractory catalyst support by impregnation with an aqueous solution of such as hexammonium platinum tetrasulfite. The resulting catalysts contain relatively small total amounts of platinum-group metal positioned primarily at the surface, yet are as highly active as catalysts uniformly impregnated throughout the body of the pellet and containing much larger amounts of platinum-group metal. The catalyst further can contain thenium.