Abstract: A process for converting hydrocarbons by contacting a hydrocarbon feedstream under hydrocarbon conversion conditions with a large crystal zeolite catalyst. The large crystal zeolite of the catalyst used in the hydrocarbon conversion process is made by heating an aqueous zeolite synthesis mixture under agitation to a temperature equal to or less than the effective nucleation temperature of the synthesis mixture. After this step, the aqueous synthesis mixture is heated in the absence of agitation to a temperature equal to or greater than the effective nucleation temperature of the aqueous zeolite synthesis mixture. The process finds particular application in hydrocarbon conversion processes where reduced non-selective acidity is important for reaction selectivity and/or the maintenance of catalyst activity, e.g., toluene disproportionation, dealkylation, alkylation, and transalkylation.

Abstract: Large crystal zeolites are prepared by heating a zeolite synthesis mixture under agitation to a temperature equal to or less than the effective nucleation temperature of the zeolite synthesis mixture and thereafter the zeolite synthesis mixture is heated without agitation to a temperature equal to or greater than the effective nucleation temperature of the zeolite synthesis mixture.