Process for preparing a heteroatom-comprising silicate

摘要

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.

主权项

1. A process for preparing a silicate, the silicate comprising silicon, oxygen and at least one heteroatom selected from the group consisting of Ga and Zn, the process comprising:
(1) preparing a colloidal aqueous solution from at least one silicon dioxide source, at least one tetraalkylammonium compound comprising R1R2R3R4N+, wherein each of R1 and R2 is methyl and both R3 and R4 are n-propyl, at least one base, a sheet silicate of the RUB-39 structure and at least one heteroatom source selected from the group consisting of a Ga source and a Zn source; (2) hydrothermally crystallizing by heating the colloidal aqueous solution obtained in (1) to a temperature in the range from greater than the boiling temperature of the colloidal aqueous solution under the selected pressure to 180° C. at standard pressure, thereby obtaining a suspension comprising at least one silicate comprising silicon, oxygen and at least the heteroatom selected from the group consisting of Ga and Zn, wherein the colloidal aqueous solution obtained in (1), before heating in (2), comprises silicon, calculated as SiO2, gallium or zinc, calculated as Ga2O3 and ZnO, respectively, dimethyl-di-n-propylammonium hydroxide (DMDPAH) as the tetraalkylammonium compound, water and the sheet silicate of the RUB-39 structure SiO2:(Ga2O3 or ZnO):DMDPAH:water:sheet silicate of the RUB-39 structure in the weight ratios 1:(0.003-0.03):(0.8-3):(8-12):(0.005-0.1).