The present disclosure relates to a preparing method of a zeolite core/silica zeolite shell composite, which includes adding a zeolite seed crystal into a gel solution containing a silicon-source compound, a structure directing agent and a fluorine anion-source compound, and then, crystallizing the gel solution for growing a silica zeolite shell containing a crystal structure which is coherent with that of the zeolite seed crystal; a zeolite core/silica zeolite shell composite prepared by the preparing method above; and catalytic use of the zeolite core/silica zeolite shell composite.

Described is a selective catalytic reduction catalyst comprising a zeolitic framework material of silicon and aluminum atoms, wherein a fraction of the silicon atoms are isomorphously substituted with a tetravalent metal. The catalyst can include a promoter metal such that the catalyst effectively promotes the reaction of ammonia with nitrogen oxides to form nitrogen and H.sub.2O selectively over a temperature range of 150 to 650 C. A method for selectively reducing nitrogen oxides and an exhaust gas treatment system are also described.

A method for synthesizing small crystals of silicoaluminophosphate-34 (SAPO-34) molecular sieves with high structural purity. The method includes forming a first slurry and a second slurry which are aged separately to form a first aged slurry and a second aged slurry. The first slurry includes a first source of phosphorus, a first source of aluminium, a first source of silicon, and at least one first organic structure directing agent. The second slurry includes a second source of phosphorus, a second source of aluminium, a second source of silicon, and at least one second organic structure directing agent. Then, the first aged slurry and the second aged slurry are combined to form a mixture of aged slurries. Finally, crystallization of silicoaluminophosphate molecular sieves comprising the SAPO-34 molecular sieves is induced from the mixture of aged slurries.

Embodiments of processes for producing propylene utilize a dual catalyst system comprising a mesoporous silica catalyst impregnated with metal oxide and a mordenite framework inverted (MFI) structured silica catalyst downstream of the mesoporous silica catalyst, where the mesoporous silica catalyst includes a pore size distribution of at least 2.5 nm to 40 nm and a total pore volume of at least 0.600 cm.sup.3/g, and the MFI structured silica catalyst has a total acidity of 0.001 mmol/g to 0.1 mmol/g. The propylene is produced from the butene stream via metathesis by contacting the mesoporous silica catalyst and subsequent cracking by contacting the MFI structured silica catalyst.

Embodiments relate to a cerium-containing nano-coating composition, the composition including an amorphous matrix including one or more of cerium oxide, cerium hydroxide, and cerium phosphate; and crystalline regions including one or more of crystalline cerium oxide, crystalline cerium hydroxide, and crystalline cerium phosphate. The diameter of each crystalline region is less than about 50 nanometers.

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.

The present disclosure is directed to processing for preparing crystalline pure-silica and heteroatom-substituted LTA frameworks in fluoride media using a simple organic structure-directing agent (OSDA), having a structure of Formula (I):

##STR00001##

where substituents R.sup.1 to R.sup.9 are defined herein. Aluminosilicate LTA is an active catalyst for the methanol to olefins reaction with higher product selectivities to butenes as well as C5 and C6 products than the commercialized catalysts. Titanosilicate LTA is an active catalyst for the epoxidation of allyl alcohol using aqueous H.sub.2O.sub.2.

The present invention relates to a method for producing graphene on a face-centered cubic metal catalyst having a plane oriented in one direction, and more particularly to a method of producing graphene on a metal catalyst having the (100) or (111) crystal structure and a method of producing graphene using a catalyst metal foil having a single orientation, obtained by electroplating a metal catalyst by a pulse wave current and annealing the metal catalyst. The invention also relates to a method of producing graphene using a metal catalyst, and more particularly to a method of producing graphene, comprising the steps of: alloying a metal catalyst with an alloying element; forming step structures on the metal catalyst substrate in an atmosphere of a gas having a molecular weight of carbon; and supplying hydrocarbon and hydrogen gases to the substrate. On unidirectionally oriented metal catalyst prepared according to the present invention, graphene can be grown uniformly and epitaxially. Moreover, a method for producing graphene according to the present invention can form monolayer graphene by epitaxially growing graphene while increasing the growth rate of graphene.

A zeolite has a CHA structure, a SiO.sub.2/Al.sub.2O.sub.3 composition ratio less than 15, and potassium in an amount of about 0.1% by mass to about 1% by mass in terms of K.sub.2O.

The present invention relates to a process for process for the preparation of a zeolitic material which process comprises (i) providing a boron-containing zeolitic material and (ii) deboronating the boron-containing zeolitic material by treating the boron-containing zeolitic material with a liquid solvent system thereby obtaining a deboronated zeolitic material, which liquid solvent system does not contain an inorganic or organic acid, or a salt thereof.