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.

Selective conversion from cyclohexene to methylcyclopentene can occur via skeletal isomerization reaction under mild temperature and near atmospheric pressure with the existence of a catalyst structure as described herein. The catalyst structure includes a porous zeolite as the support and one or more loaded metals to further modify its acidity and pore structures. Industrially available cyclohexene feedstock can be effectively converted to a high value-added product methylcyclopentene with over 90 wt % conversion and 95 wt % selectivity, which is highly profitable for potential application in the fine chemical industry.

The invention includes an additive for maximizing production of olefins. The additive comprises a ZSM-5 molecular sieve, at least one inorganic oxide, and phosphorus oxide. The ZSM-5 molecular sieve has iron in the framework, and the additive comprises at least 0.5 weight percent iron, as measured as iron oxide, in the molecular sieve framework. The additive is useful for maximizing production of olefins in a FCC process.

A method of making a crystalline molecular sieve of MFI framework type, preferably ZSM-5, from a synthesis mixture comprising at least one source of tetravalent element (Y), at least one source of trivalent element (X), at least one source of alkali metal hydroxide (MOH), at least one structure directing; (R) and water, said synthesis mixture having the following molar composition: YO.sub.2, (p)X.sub.2O.sub.3: (q) MOH: (r) R: (s) H.sub.2O, wherein (p) is from 0.005 to 0.025, (q) is from 0.05 to 0.5, (r) is from 0.05 to 0.15 and (s) is from 35 to 45, wherein the ratio of the largest dimension (L) to the smallest dimension (S) of each crystal of the molecular sieve product is at least 5, and the smallest dimension (S) is from 20 nm to 200 nm.

Disclosed are processes for conversion of a feedstock comprising C.sub.8+ aromatic hydrocarbons to lighter aromatic products in which the feedstock and optionally hydrogen are contacted in the presence of the catalyst composition under conversion conditions effective to dealkylate and transalkylate said C.sub.8+ aromatic hydrocarbons to produce said lighter aromatic products comprising benzene, toluene and xylene. The catalyst composition comprises a zeolite, a first metal, and a second metal, and is treated with a source of sulfur and/or a source of steam.

A lower olefin by using a zeolite catalyst, a composite catalyst capable of further extending the lifetime of catalytic activity, a method for producing the composite catalyst, a method for producing a lower olefin by using the composite catalyst, and a method for regenerating a composite catalyst in the method for producing a lower olefin are provided. The composite catalyst is a catalyst for producing a lower olefin from a hydrocarbon feedstock. This composite catalyst is constituted of a zeolite being a crystalline aluminosilicate containing gallium and iron or iron and further having a framework with 8- to 12-membered ring, and of silicon dioxide. By using the composite catalyst, a lower olefin can be continuously produced over a long period of time.

A catalyst comprising a microporous crystalline metallosilicate having a Constraint Index of 12, or 10, or 8, or 6 or less, a binder, a Group 1 alkali metal or a compound thereof and/or a Group 2 alkaline earth metal or a compound thereof, a Group 10 metal or a compound thereof, and, optionally, a Group 11 metal or a compound thereof; wherein the catalyst is calcined in a first calcining step before the addition of the Group 10 metal or compound thereof and optionally the Group 11 metal or compound thereof; and wherein the first calcining step includes heating the catalyst to first temperatures of greater than 500° C.; and wherein the catalyst is calcined in a second calcining step after the addition of the Group 10 metal or compound thereof and optionally the Group 11 metal or compound thereof wherein the second calcining step includes heating the catalyst to temperatures of greater than 400° C.

A rare earth- and phosphorus-containing molecular sieve of MFI structure rich in mesopores has a ratio of n(SiO.sub.2)/n(Al.sub.2O.sub.3) of more than 15 and less than 70. The molecular sieve has a content of phosphorus of 1-15 wt %, calculated as P.sub.2O.sub.5 and based on the dry weight of the molecular sieve. The content of the supported metal in the molecular sieve is 1-10 wt % supported metal M1 and 0.1-5 wt % supported metal M2 based on the oxide of the supported metal and the dry weight of the molecular sieve. The supported metal M1 is one or two selected from lanthanum and cerium, and the supported metal M2 is one selected from iron, cobalt, nickel, copper, manganese, zinc, tin, bismuth and gallium; the volume of mesopores in the molecular sieve represents 40-70% by volume of the total pore volume of the molecular sieve by volume.

Porous zeolite monolith compositions for the catalytic cracking of alkanes. The compositions may be prepared layer by layer using a 3D printer such that the compositions comprise a plurality of micropores and a plurality of mesopores and may be characterized by macro-meso-microporosity.

A catalyst for converting hydrocarbon, a method of making the same, and a method of using the same are provided. Such a catalyst includes a zeotype microporous material, a binder material, and a metal phosphide, which can be in a range of from 0.01% to 10% by weight of a total weight of the catalyst. For example, such a catalyst can be used to convert light alkene or alkane into aromatic hydrocarbon such as benzene, toluene, xylenes, and a combination thereof. The alkene may be ethylene, propylene, butylene, or a combination thereof. The alkene may be supplied directly or from a stream converted from light alkane such as methane, ethane, propane, butane, or a combination thereof.