Patent ID: 7375050

Claim:
A method for preparing silicoaluminophosphate molecular sieves of CHA framework type, the method comprising: (a) forming a synthesis mixture comprising a source of aluminum, a source of phosphorus, at least two organic templates R 1 and R 2 , a source of silicon, and colloidal seeds in an amount selected to form crystalline molecular sieves having a desired crystal size, wherein R 1 comprises tetraethyl ammonium compounds, R 2 is a compound selected from the group consisting of dipropylamine, isopropylamine, cyclohexylamine, methylbutylamine, morpholine, diethanolamine, trimethylethylenediamine, triethylamine, and compounds containing N, N-dimethylamino moieties, and the molar ratio of organic template (R 1 +R 2 ) to aluminum (Al) in the synthesis mixture is ≦1.1; and (b) forming silicoaluminophosphate crystalline molecular sieves of CHA framework type and desired crystal size from the synthesis mixture.