Hydrocracking catalyst and process

A hydrocracking process comprising contacting a hydrocarbon feedstock with a catalyst under hydrocracking conditions in the presence of hydrogen and in an atmosphere which contains no more than about 200 ppmv ammonia so as to produce a product of lower average boiling point, said catalyst being devoid of a nonzeolitic molecular sieve and comprising one or more hydrogenation components in combination with a support comprising an inorganic refractory oxide, zeolite Beta in a form catalytically active for cracking hydrocarbons, and a Y zeolite catalytically active for cracking hydrocarbons, said Y zeolite having a unit cell size between about 24.20 and 24.35 angstroms and a water vapor sorption capacity at 25.degree. C. and p/p.sub.o value of 0.10 of less than about 10 weight percent, wherein said catalyst contains between about 15 and 50 weight percent of said Y zeolite.

A hydrocracking process comprising contacting a gas oil feedstock with a catalyst under hydrocracking conditions in the presence of hydrogen and in an atmosphere which contains no more than about 200 ppmv ammonia so as to produce a product of lower average boiling point, said catalyst being devoid of a nonzeolitic molecular sieve and comprising one or more hydrogenation components in combination with a support comprising an inorganic refractory oxide binder, zeolite Beta in a form catalytically active for cracking hydrocarbons, and LZ-10 zeolite, the LZ-10 zeolite having a unit cell size between about 24.25 and 24.35 angstroms and a water vapor sorption capacity at 4.6 mm water vapor partial pressure and 25.degree. C. of less than about 8.0 percent by weight of the zeolite, wherein said catalyst contains between about 15 and about 50 weight percent of said LZ-10 zeolite.