| 摘要 |
Crystalline alumonosilicates having a silica to alumina molar ratio greater than 12 are produced by mixing a source of silica, a source of alumina, a source of alkali metal, water and a source of ammonium ions, e.g. ammonia or an ammonium salt, in the absence of an alcohol or alkylene oxide, in the molar proportions (expressed in the case of the silica and alumina sources in terms of the equivalent moles of the oxide, in the case of the alkali metal source in terms of the equivalent moles of the hydroxide ¢MOH! and in the case of the source of ammonium ions in terms of free ammonia): SiO2 : A1203 greater than 12:1 MOH : A12O3 in the range from 1:1 to 20:1 SiO2 : NH3 in the range from 1:1 to 200:1 H2O : MOH in the range from 30:1 to 300:1 and maintaining the composition at elevated temperature, such as 120 to:210.degree.C, for a period such that crystallisation occurs, typically greater than 4 hours. The crystalline aluminosilicates so-prepared are useful as catalysts and catalyst supports. |
