| abstract |
Crystalline aluminosilicates having a high silica to alumina molar ratio are prepared by mixing a source of silica, a source of alumina, a source of alkali metal, water and one or more substituted neopentylamines having the formula: <IMAGE> wherein R2 is H, OH or NH2 and R1 is a C1 to C6 alkyl group, and maintaining the mixture under conditions of elevated temperature and pressure, typically in the range from 80 DEG to 210 DEG C. and autogenous pressure for a time sufficient to effect formation of the aluminosilicate, typically not less than 4 hours. The molar ratio of silica to alumina in the initial mixture is suitably in the range from 10:1 to 150:1 and the amounts of alkali metal and neopentylamine are suitably in the range from 2:1 to 0.02:1 and 10:1 to 0.02:1 respectively moles per mole equivalent of total silica and alumina in the respective sources. Depending on the ratio of silica to alumina in the initial mixture crystalline aluminosilicates having a mordenite structure or a ZSM-5 type zeolite structure or mixtures thereof may be prepared. Mordenites having a silica to alumina ratio greater than 10:1 can be prepared. |