Surface silylated zeolite catalysts, and processes for the preparation, and use of said catalysts in the production of high octane gasoline

Abstract

A novel zeolite hydrocracking catalyst which contains NH.sub.4.sup.+ sites, at ambient temperatures, and surface sites constituted of a chemisorbed silica-containing species, and process for producing said catalyst. The process for preparation of the catalyst includes a series of steps: an initial step wherein an acid zeolite, or acid zeolite hydrocracking catalyst, is treated with an agent, e.g., a nitrogen-containing compound, suitably ammonia, to convert the H.sup.+ sites throughout said zeolite framework to NH.sub.4.sup.+ sites, and a subsequent post treatment of said NH.sub.4.sup.+ zeolite with an organosilane to silylate, modify and form on the surface of said zeolite a chemisorbed silica species, e.g., --O--Si(CH.sub.3).sub.3. The surface silylated catalyst is useful for the production of high octane gasoline. When employed at elevated temperatures in a hydro-cracking operation the catalyst will evolve ammonia and convert to a surface silylated H.sup.+ zeolite catalyst to produce a high octane gasoline, at low hydrogen consumption.

Dependencies are inferred from the claim text.