Abstract:
PROBLEM TO BE SOLVED: To provide an organotemplate-free synthetic process for the production of a zeolitic material having a BEA framework structure comprising YOand optionally comprising XO.SOLUTION: The process comprises the steps of: (1) preparing a mixture comprising seed crystals, at least one source for YOand at least one source for XO; (2) crystallizing the mixture; and (6) subjecting the zeolitic material having a BEA framework structure to an ion-exchange procedure, wherein Y is a tetravalent element, and X is a trivalent element. The seed crystals comprise zeolitic material having a BEA framework structure. In the step (6), at least one ionic non-framework element contained in the zeolitic material having a BEA framework is ion-exchanged against Fe and/or Cu.
Abstract:
A process for the preparation of an isomorphously substituted layered silicate comprising (1) providing a mixture containing silica or a precursor thereof, at least one structure directing agent (SDA) allowing for the crystallization of the layered silicate, and water; (2) heating the mixture obtained according to (1) under hydrothermal conditions; (3) adding at least one source at least one element suitable for isomorphous substitution; (4) heating the mixture obtained according to (3) under hydrothermal conditions.
Abstract:
The present invention relates to a ferrous zeolite, wherein the number of iron centers, relative to the zeolite, is greater than the number of cation positions of the zeolite. The present invention further relates to a ferrous zeolite that can be produced by gas phase reaction with iron pentacarbonyl, comprising a greater specific surface area than analogous ferrous zeolites produced by ion exchange and/or more hydrothermally stable than analogous ferrous zeolites produced by ion exchange. The present invention further relates to a ferrous zeolite of BETA structure that can be produced by gas phase reaction with iron pentacarbonyl, wherein the number of iron clusters greater than 10 nm is less than 15 wt%, relative to the total amount of iron. The present invention further relates to a method for producing ferrous zeolithic material, characterized in that doping with iron takes place by means of a gas phase reaction using iron pentacarbonyl. The present invention further relates to a method for catalytically reducing nitrogen oxides by adding ammoniac and using catalysts comprising said ferrous zeolithic material.
Abstract:
The present invention relates to a process for the preparation of a zeolitic material having a CHA framework structure, said zeolitic material comprising zeolite crystals having a core-shell structure, wherein said process comprises the steps of (1) providing a mixture comprising one or more sources for Z2O5, one or more sources for X2O3, optionally one or more structure directing agents, and seed crystals having a CHA framework structure, wherein the CHA framework structure of the seed crystals comprises Y02, X2O3, and optionally Z2O5, and wherein the seed crystals have a diameter of 450 nm or greater; (2) crystallizing the mixture provided in (1) to afford zeolite crystals comprising a core of seed crystal provided in step (1 ) and a shell crystallized on the seed crystal; wherein Z is a pentavalent element, Y is a tetravalent element, and X is a trivalent element, and wherein preferably one or more sources for YO2 are further provided in step (1 ).
Abstract:
The present invention relates to a process for the preparation of a layered silicate containing at least silicon and oxygen, comprising (1) providing a mixture containing silica and/or at least one silica precursor, water, at least one tetraalkylammonium compound selected from the group consisting of diethyldimethylammonium compound, a triethylmethylammonium compound, and a mixture of a diethyldimethylammonium and a triethylmethylammonium compound, and at least one base, and optionally at least one suitable seeding material; and (2) heating of the mixture obtained according to (1) under autogenous pressure (hydrothermal conditions) to a temperature in the range of from to 120 to 160 °C for a period in the range of from 5 to 10 days to give a suspension containing the layered silicate.
Abstract:
The present invention relates to a process for the preparation of a pillared silicate compound comprising a layered silicate structure and bridging silicon atoms located between adjacent silicate layers of the silicate structure, wherein said bridging silicon atoms form at least one covalent bond to each of the adjacent silicate layers, said process comprising (1) providing one or more layered silicates; (2) adding said one or more layered silicates to a solvent system, wherein the resulting mixture has a pH of 5 or less; and (3) subjecting the mixture obtained in step (2) to solvothermal conditions; wherein no silicon-containing compound according to formula (I) R4-mSi[-(SiR2)n-R]m (I) is used at any point of the process up to and including step (3), wherein m is 1, 2, 3, or 4, and n is an integer greater than or equal to 0, wherein when n is equal to 0, one or more residues R are leaving groups, and wherein none of the residues R contains Si, as well as to a pillared silicate compound per se, preferably as obtained and/or obtainable according to the inventive process as well as to the use of the inventive compounds. A further process is disclosed wherein a sulfur oxoacid is present in step (2), and wherein a silicon-containing compound may or may not be used.
Abstract:
A method of dehydration of at least one compound (A) comprising, in the chain form, -at least one hydroxyl group and -at least one carbonyl functionality selected from the group consisting of aldehyde (CHO), ke- tone (CO) and carboxylic acid (COOH) and mixtures thereof,in the presence of at least one zeolite which is (a) obtainable from an organotemplate-free synthetic process and (b) isomorphously substituted comprising silicon, aluminum and at least one further metal wherein the at least one further metal is selected from the group consisting of the elements of Group 3 to 14 in Period 4 to 6and mixtures thereof.
Abstract:
A process for the production of a pillared silicate comprises: (i) providing a layered silicate; (ii) interlayer expanding the layered silicate provided in step (i) comprising a step of treating the layered silicate with one or more swelling agents; (iii) treating the interlayer expanded silicate with one or more hydrolysable silicon containing compounds; (iv) treating the interlayer expanded compound with an aqueous solution to obtain a pillared silicate; (v) removing at least a portion of the one or more swelling agents from the pillared silicate; (vi) impregnating the pillared silicate with one or more elements selected from the group consisting of Fe, Ru, Ir, and combinations of two or more thereof, as well as to a pillared silicate optionally obtainable from said process and its use, in particular in a process for the production of one or more olefins.
Abstract:
The present invention relates to a process for the preparation of a silicate compound, comprising (1) providing at least one layered silicate; and (2) mixing said layered silicate with water and at least one silicon containing compound according to formula R4-mSi[-(SiR2)n-R]m wherein at least one residue R is a leaving group and none of the residues R contains Si; m is 0, 1, 2, 3, or 4; and n is an integer greater than or equal to 0.
Abstract:
The present invention relates to a process for the preparation of an isomorphously substituted RUB-36 silicate comprising (1) providing a mixture containing silica, preferably amorphous silica, and/or at least one silica precursor, water, at least one suitable structure directing agent, (2) heating the mixture obtained according to (1) under hydrothermal conditions to give a suspension containing an RUB-36 silicate, (3) separating the RUB-36 silicate, wherein (a) either the mixture according to (1) contains at least one element suitable for isomorphous substitution and/or (b) the separated RUB-36 silicate according to (3) is subjected to isomorphous substitution.