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 invention relates to a method for producing a layered silicate containing at least Ga and/or Zn and a tectosilicate based thereon, preferably with an RRO structure, to the layered silicate and tectosilicate and to the use of silicates, in particular tectosilicate, preferably as catalysts.
Abstract:
Método para la producción de un silicato que contiene por lo menos silicio, oxígeno y por lo menos un heteroátomo elegido de entre el grupo compuesto por Ga y Zn, incluyendo (1) producción de una solución acuosa coloidal de por lo menos una fuente de dióxido de silicio, por lo menos un compuesto de tetraalquilamonio que incluye R1R2R3R4N + , donde R1 y R2 son metilo y tanto R3 como también R4 son n-propilo, por lo menos una base, por lo menos un agente auxiliar de cristalización y por lo menos una fuente de heteroátomo, elegida de entre el grupo compuesto por una fuente de Ga y una fuente de Zn; (2) cristalización hidrotérmica mediante calentamiento de la solución acuosa coloidal obtenida bajo (1) a una temperatura en el rango que va desde más de la temperatura de ebullición presente bajo la presión elegida de la solución acuosa coloidal, hasta 180 °C a presión normal, para obtener una suspensión que contiene por lo menos un silicato, que contiene silicio, oxígeno y por lo menos el heteroátomo elegido de entre el grupo consistente en Ga y Zn, donde como agente auxiliar de cristalización en (1) se emplea un silicato con la estructura del silicato obtenido según (2).
Abstract:
The present invention relates to a process for the preparation of a zeolitic material having a BEA framework structure comprising the steps of: (i) providing one or more zeolitic materials having a BEA framework structure, wherein the BEA framework structure comprises YO2 and X2O3, wherein Y is a tetravalent element, and X is a trivalent element; (ii) subjecting the one or more zeolitic materials provided in step (i) to a procedure for removing at least a portion of X, preferably tetrahedrally coordinated X, from the BEA framework structure; wherein the Y:X molar ratios of the one or more zeolitic materials provided in step (i) are respectively comprised in the range of from 1 to 50.
Abstract:
The present invention relates to a process for preparing at least one sheet silicate comprising Ga and/or Zn, and based thereon, a framework silicate, preferably of the RRO structure type, to the sheet silicate and framework silicate themselves and to the uses of the silicates, especially of the framework silicate, preferably as catalysts.
Abstract:
The present invention relates to a process for the preparation of a zeolitic material having a BEA framework structure comprising the steps of: (i) providing one or more zeolitic materials having a BEA framework structure, wherein the BEA framework structure comprises YO2 and X2O3, wherein Y is a tetravalent element, and X is a trivalent element; (ii) subjecting the one or more zeolitic materials provided in step (i) to a procedure for removing at least a portion of X, preferably tetrahedrally coordinated X, from the BEA framework structure; wherein the Y:X molar ratios of the one or more zeolitic materials provided in step (i) are respectively comprised in the range of from 1 to 50.