Patent ID: 8383080

Claim:
A method of synthesizing a crystalline material comprising a CHA framework-type molecular sieve and having a composition involving the molar relationship: ( n )X 2 O 3 :YO 2 , wherein X is a trivalent element, Y is a tetravalent element, and n is less than 0.07, the method comprising: (a) preparing a reaction mixture capable of forming said material, said mixture comprising a source of water, a source of an oxide of a tetravalent element Y, an organic directing agent and, optionally, a source of an oxide of a trivalent element X; (b) maintaining said reaction mixture under conditions sufficient to form crystals of said crystalline material; wherein the mixture is aged at about room temperature from about 30 minutes to about 120 hours before colloidal LEV seeds are added, followed by heating the mixture while tumbling at a temperature of about 140° C. to about 200° C. for about 1 to about 120 hours to form said crystalline material; (c) recovering said crystalline material and removing the directing agent from the recovered crystalline material; and (d) contacting said crystalline material with an atmosphere containing steam at a temperature of about 400° C. to about 650° C. for a time of about 8 hours to about 170 hours, said atmosphere comprises a steam partial pressure of about 1 psia to about 25 psia (7 to 172 kPa); wherein the directing agent is removed from the crystalline material recovered in (c) prior to contacting said crystalline material with said atmosphere containing steam.