Method for preparing CHA-type molecular sieves using an alkali metal silicate precursor and novel structure directing agents

摘要

The present invention is directed to a process for preparing CHA-type molecular sieves using a colloidal aluminosilicate composition containing a cationic structure directing agent selected from the group consisting of N-cyclohexyl-N-methylpyrrolidinium, N-cyclohexyl-N-ethylpyrrolidinium, N-methyl-N-(3-methylcyclohexyl)pyrrolidinium, N-ethyl-N-(3-methylcyclohexyl)pyrrolidinium, N-methyl-N-(2-methylcyclohexyl)-pyrrolidinium, N-ethyl-N-(2-methylcyclohexyl)pyrrolidinium, and mixtures thereof.

主权项

1. A method of preparing a CHA-type molecular sieve, comprising:
(a) preparing a reaction mixture containing: (1) an alkali metal silicate; (2) one or more sources of one or more oxides selected from the group consisting of oxides of trivalent elements, pentavalent elements, and mixtures thereof; (3) a cationic structure directing agent selected from the group consisting of N-cyclohexyl-N-methylpyrrolidinium, N-cyclohexyl-N-ethylpyrrolidinium, N-methyl-N-(3-methylcyclohexyl)pyrrolidinium, N-ethyl-N-(3-methylcyclohexyl)pyrrolidinium, N-methyl-N-(2-methylcyclohexyl)pyrrolidinium, N-ethyl-N-(2-methylcyclohexyl)pyrrolidinium, and mixtures thereof; (4) at least one source of an element selected from Groups 1 and 2 of the Periodic Table; (5) hydroxide ions; and (6) water; and (b) subjecting the reaction mixture to crystallization conditions sufficient to form crystals of the CHA-type molecular sieve.