Embodiments of catalyst systems and methods of synthesizing catalyst systems are provided. The catalyst system may include a core comprising a zeolite; and a shell comprising a microporous fibrous silica. The shell may be in direct contact with at least a majority of an outer surface of the core. The catalyst system may have a Si/Al molar ratio greater than 5. At least a portion of the shell may have a thickness of from 50 nanometers (nm) to 600 nm.

A nano-sized mesoporous zeolite beta composition and processes for the synthesis and use of the nano-sized mesoporous zeolite beta. The nano-sized mesoporous zeolite beta is synthesized using a hydrothermal treatment without drying and calcination of the zeolite prior to or after hydrothermal treatment. A process for hydrocracking a hydrocarbon feedstock using the nano-sized mesoporous zeolite beta is also provided.

A nano-sized mesoporous zeolite beta composition and processes for the synthesis and use of the nano-sized mesoporous zeolite beta. The nano-sized mesoporous zeolite beta is synthesized using desilication without the addition of a structure directing agent (SDA). A process for hydrocracking a hydrocarbon feedstock using the nano-sized mesoporous zeolite beta is also provided

A modified Y-type molecular sieve has a rare earth content of about 4% to about 11% by weight on the basis of the oxide, a phosphorus content of about 0.05% to about 10% by weight on the basis of P.sub.2O.sub.5, a sodium content of no more than about 0.5% by weight on the basis of sodium oxide, a gallium content of about 0.1% to about 2.5% by weight on the basis of gallium oxide, and a zirconium content of about 0.1% to about 2.5% by weight on the basis of zirconia; and the modified Y-type molecular sieve has a total pore volume of about 0.36 mL/g to about 0.48 mL/g, a percentage of the pore volume of secondary pores having a pore size of 2-100 nm to the total pore volume of about 20% to about 40%.

A modified Y-type molecular sieve has a rare earth content of about 4% to about 11% by weight on the basis of the oxide, a phosphorus content of about 0.05% to about 10% by weight on the basis of P.sub.2O.sub.5, a sodium content of no more than about 0.5% by weight on the basis of sodium oxide, a gallium content of about 0.1% to about 2.5% by weight on the basis of gallium oxide, and a zirconium content of about 0.1% to about 2.5% by weight on the basis of zirconia; and the modified Y-type molecular sieve has a total pore volume of about 0.36 mL/g to about 0.48 mL/g, a percentage of the pore volume of secondary pores having a pore size of 2-100 nm to the total pore volume of about 20% to about 40%.

The present invention relates to a method for preparing ZSM-5 zeolite. The present invention can provide a method for preparing ZSM-5 zeolite comprising the steps of: preparing a first solution in a solution state by heating a mixture comprising a silica source, an alumina source, a neutralizing agent and a crystalline ZSM-5 nucleus; preparing a reaction mother liquid by mixing a second solution comprising salts into the first solution; and continuously crystallizing by continuously supplying the reaction mother liquid to a hydrothermal synthesis reactor, wherein formula [1] below is satisfied.
0.20≤W.sub.a/W.sub.b≤0.40  Formula [1]

A modified Y-type molecular sieve has a rare earth content of about 4-11% by weight on the basis of rare earth oxide, a sodium content of no more than about 0.5 wt % by weight on the basis of sodium oxide, a zinc content of about 0.5-5% by weight on the basis of zinc oxide, a phosphorus content of about 0.05-10% by weight on the basis of phosphorus pentoxide, a framework silica-alumina ratio of about 7-14 calculated on the basis of SiO.sub.2/Al.sub.2O.sub.3 molar ratio, a percentage of non-framework aluminum content to the total aluminum content of no more than about 10%, and a percentage of the pore volume of secondary pores having a pore size of 2-100 nm to the total pore volume of about 20-40%. The modified Y-type molecular sieve has a high crystallinity and a high thermal and hydrothermal stability, and is rich in secondary pores.

A modified Y-type molecular sieve has a rare earth content of about 4-11% by weight on the basis of rare earth oxide, a sodium content of no more than about 0.5 wt % by weight on the basis of sodium oxide, a zinc content of about 0.5-5% by weight on the basis of zinc oxide, a phosphorus content of about 0.05-10% by weight on the basis of phosphorus pentoxide, a framework silica-alumina ratio of about 7-14 calculated on the basis of SiO.sub.2/Al.sub.2O.sub.3 molar ratio, a percentage of non-framework aluminum content to the total aluminum content of no more than about 10%, and a percentage of the pore volume of secondary pores having a pore size of 2-100 nm to the total pore volume of about 20-40%. The modified Y-type molecular sieve has a high crystallinity and a high thermal and hydrothermal stability, and is rich in secondary pores.

The present invention relates to a catalyst for producing olefins from dehydrogenation of alkane having 2 to 5 carbon atoms and a method for producing olefins using said catalyst, wherein said catalyst comprises a hierarchical zeolite nanosheet having a silica to alumina (SiO.sub.2/AI.sub.2O.sub.3) ratio more than 120 and group X metal(s) in a range of 0.3 to 5% by weight. The catalyst according to the conversion of precursor to yields and high olefins selectivity.

A modified Y-type molecular sieve has a modifying metal content of about 0.5-6.3 wt % calculated on the basis of an oxide of the modifying metal and a sodium content of no more than about 0.5 wt % calculated on the basis of sodium oxide. The modifying metal is magnesium and/or calcium. The modified Y-type molecular sieve has a proportion of non-framework aluminum content to the total aluminum content of no more than about 20%, a total pore volume of about 0.33-0.39 ml/g, a proportion of the pore volume of secondary pores having a pore size of 2-100 nm to the total pore volume of about 10-25%, a lattice constant of about 2.440-2.455 nm, a lattice collapse temperature of not lower than about 1040° C., and a ratio of B acid to L acid in the total acid content of no less than about 2.30.