Disclosed are a catalyst system and its use in a process for the conversion of a feedstock containing C.sub.8+ aromatic hydrocarbons to produce light aromatic products, comprising benzene, toluene and xylene. The catalyst system comprises (a) a first catalyst bed comprising a first catalyst composition, said first catalyst composition comprising a zeolite having a constraint index of 3 to 12 combined (i) optionally with at least one first metal of Group 10 of the IUPAC Periodic Table, and (ii) optionally with at least one second metal of Group 11 to 15 of the IUPAC Periodic Table; and (b) a second catalyst bed comprising a second catalyst composition, said second catalyst composition comprising (i) a meso-mordenite zeolite, combined (ii) optionally with at least one first metal of Group 10 of the IUPAC Periodic Table, and (iii) optionally with at least one second metal of Group 11 to 15 of the IUPAC Periodic Table, wherein said meso-mordenite zeolite is synthesized from TEA or MTEA and having a mesopore surface area of greater than 30 m.sup.2/g and said meso-mordenite zeolite comprises agglomerates composed of primary crystallites, wherein said primary crystallites have an average primary crystal size as measured by TEM of less than 80 nm and an aspect ratio of less than 2.

Compositions and methods for preparing mesoporous and/or mesostructured materials from low SAR zeolites are provided herewith. In particular, methods are provided that involve: (a) providing a low SAR zeolite, (b) optionally subjecting the low SAR zeolite to an acid framework modification, and (c) subjecting the framework-modified zeolite to a mesopore formation treatment. The resulting mesoporous zeolites can have bi-modal mesoporosity and higher aluminum contents relative to existing mesoporous zeolites.

Crystalline molecular sieves and their synthesis using quaternary N-methyl-diisoalkylammonium cations as organic structure directing agents are disclosed. The structure directing agent has the following structure (1):

##STR00001##

in which R.sup.1 is selected from hydrogen, a methyl group, an ethyl group, a propyl group, and a hydroxymethyl group; and R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are independently selected from a methyl group, an ethyl group, and a propyl group.

Crystalline molecular sieves and their synthesis using quaternary N-methyl-diisoalkylammonium cations as organic structure directing agents are disclosed. The structure directing agent has the following structure (1): ##STR00001##
in which R.sup.1 is selected from hydrogen, a methyl group, an ethyl group, a propyl group, and a hydroxymethyl group; and R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are independently selected from a methyl group, an ethyl group, and a propyl group.

Compositions and methods for preparing mesoporous and/or mesostructured materials from low SAR zeolites are provided herewith. In particular, methods are provided that involve: (a) providing a low SAR zeolite, (b) optionally subjecting the low SAR zeolite to an acid framework modification, and (c) subjecting the framework-modified zeolite to a mesopore formation treatment. The resulting mesoporous zeolites can have bi-modal mesoporosity and higher aluminum contents relative to existing mesoporous zeolites.

Crystalline molecular sieves and their synthesis using quaternary N-methyl-diisoalkylammonium cations as organic structure directing agents are disclosed. The structure directing agent has the following structure (1):

##STR00001##

in which R.sup.1 is selected from hydrogen, a methyl group, an ethyl group, a propyl group, and a hydroxymethyl group; and R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are independently selected from a methyl group, an ethyl group, and a propyl group.

A mordenite zeolite having excellent particle uniformity and a method for preparing the same are provided. The method includes dissolving a pH-adjusting material and a silica precursor in water to provide a basic silica suspension; dissolving a structure-directing agent and an alumina precursor in water to provide an aqueous solution; dissolving a surfactant in water to provide an aqueous solution; mixing and stirring the basic silica suspension and an alumina aqueous solution to prepare a silica-alumina aqueous solution; adding an surfactant aqueous solution to the silica-alumina aqueous solution to prepare a zeolite synthesis composition; gelating the zeolite synthesis composition; and crystallizing.

The present disclosure is directed to a method of manufacture of mordenite zeolites. This is accomplished by using an improved sol-gel formulation including a water-soluble fraction of ODSO as an additional component. The resulting products are, or contain, mordenite zeolites, with increased yield.

A process for preparing an oxidic material comprising a zeolitic material having framework type AEI and a framework structure comprising a tetravalent element Y, a trivalent element X, and O, the process comprising preparing a synthesis mixture comprising water, a source of Y, a source of X comprising sodium, an AEI framework structure directing agent, and a source of sodium other than the source of X; and heating the synthesis mixture obtained from (i) to a temperature in the range of from 100 to 180 C. and keeping the synthesis mixture under autogenous pres-sure at a temperature in this range for a time in the range of at least 6 h, obtaining the oxidic material comprising a zeolitic material having framework type AEI and a framework structure comprising a tetravalent element Y, a trivalent element X, and O, comprised in its mother liquor; wherein the AEI framework structure directing agent according to (i) comprises a N, N-diethyl-2,6-dimethylpiperidinium cation.

The present disclosure is directed to a method to co-synthesize amorphous and crystalline porous materials, including a phase of crystalline solids possessing well-defined structures and uniform pore sizes, and an amorphous phase. A sol-gel formulation which includes a water-soluble fraction of ODSO as an additional component is provided that precipitates multiple solid phases.