Abstract: There is provided a coated zeolite catalyst in which the accessibility of the acid sites on the external surfaces of the zeolite is controlled and a process for converting hydrocarbons utilizing the coated zeolite catalyst. The zeolite catalyst comprises core crystals of a first zeolite and a discontinuous layer of smaller size second crystals of a second zeolite which cover at least a portion of the external surface of the first crystals The coated zeolite catalyst finds particular application in hydrocarbon conversion processes where catalyst activity in combination with zeolite structure are important for reaction selectivity, e.g., catalytic cracking, alkylation, disproportional of toluene, isomerization, and transalkylation reactions.

Abstract: A silicoaluminophosphate molecular sieve is disclosed that comprises first and second intergrown phases of a CHA framework type and an AEI framework type, wherein said first intergrown phase has an AEI/CHA ratio of from about 5/95 to about 40/60 as determined by DIFFaX analysis, the second intergrown phase has an AEI/CHA ratio of about 30/70 to about 55/45 as determined by DIFFaX analysis and said molecular sieve has a silica to alumina molar ratio (Si/Al2) from about 0.13 to about 0.24.

Abstract: A crystalline material substantially free of framework phosphorus and comprising a CHA framework type molecular sieve with stacking faults or at least one intergrown phase of a CHA framework type molecular sieve and an AEI framework type molecular sieve, wherein said material, in its calcined, anhydrous form, has a composition involving the molar relationship: (n)X2O3:YO2, wherein X is a trivalent element; Y is a tetravalent element; and n is from 0 to about 0.5. The material exhibits activity and selectivity in the conversion of methanol to lower olefins, especially ethylene and propylene.

Abstract: The present invention relates to a silicoaluminophosphate molecular sieve comprising at least one intergrown phase of molecular sieves having AEI and CHA framework types, wherein said intergrown phase has an AEI/CHA ratio of from about 5/95 to 40/60 as determined by DIFFaX analysis, using the powder X-ray diffraction pattern of a calcined sample of said silicoaluminophosphate molecular sieve. It also relates to methods for its preparation and to its use in the catalytic conversion of methanol to olefins.