Abstract: An FCC catalyst containing zeolite particles at least 50% of the outer surface of which is coated with a layer of pre-formed inorganic oxide is used in fluidized catalytic cracking of hydrocarbon feeds. The inorganic oxide layer has a thickness in the range of 10 nm to 5 &mgr;m and the ratio between the particle size of the oxide and the mean particle size of the zeolite particles is in the range of 0.001:1 to 0.5:1. The zeolite particles may be coated by contacting uncoated zeolite particles having a mean particle size in the range of 0.1 to 10 &mgr;m with an aqueous medium containing particles of the oxide having a particle size in the range of 10 to 5,000 nm, after which the particles are optionally dried or calcined. The oxide is preferably alumina. The FCC catalysts are less rapidly deactivated by contaminant metals present in heavy feeds and are less susceptible to blocking of the zeolite pores by coke.

Abstract: The invention relates to a hydrocracking catalyst containing at least one hydrogenation metal component, and particles of a cracking component of which at least 50% of the outer surface is coated with a layer of a pre-formed oxide, which layer has a thickness in the range of 10 nm to 5 .mu.m. The cracking component is either a zeolitic cracking component or an amorphous cracking component or a mixture of both. The particles may be coated with oxide by contacting uncoated particles having a mean particle size in the range of 0.1 to 10 .mu.m with an aqueous medium containing particles of the oxide to be provided as the coating having a particle size in the range of 10-5000 nm, with the ratio between the oxide particle size and the mean particle size of the cracking component particles being in the range of 0.001:1 to 0.5:1. The coating oxide is preferably alumina or silica/alumina.