CHA type zeolitic materials and methods for their preparation
The present disclosure relates to a process for the preparation of a zeolitic material having a CHA-type framework structure comprising YO 2 and X 2 O 3 , wherein the process comprises: (1) providing a mixture comprising one or more sources for YO 2 , one or more sources for X 2 O 3 , one or more tetraalkylammonium cation R 1 R 2 R 3 R 4 N + -containing compounds, and one or more tetraalkylammonium cation R 5 R 6 R 7 R 8 N + -containing compounds as structure directing agent; (2) crystallizing the mixture to obtain a zeolitic material having a CHA-type framework structure; wherein Y is a tetravalent element and X is a trivalent element, wherein R 1 , R 2 , R 3 , R 5 , R 6 , and R 7 independently from one another stand for alkyl, wherein R 4 stands for C n H 2n OH with n=1 to 6, and wherein R 8 stands for cycloalkyl.
1 . A process for preparing a zeolitic material having a CHA-type framework structure comprising YO 2 and X 2 O 3 , wherein the process comprises:
providing a mixture comprising one or more sources for YO 2 , one or more sources for X 2 O 3 , one or more tetraalkylammonium cation R 1 R 2 R 3 R 4 N + -containing compounds, and one or more tetraalkylammonium cation R 5 R 6 R 7 R 8 N + -containing compounds as structure directing agent; and
crystallizing the mixture to obtain a zeolitic material having a CHA-type framework structure;
wherein Y is a tetravalent element and X is Al,
wherein R 1 , R 2 , R 3 , R 5 , R 6 , and R 7 stand for methyl,
wherein R 4 is chosen from C n H 2n OH and n ranges from 1 to 6,
wherein R 8 stands for cyclohexyl,
wherein a molar ratio R 1 R 2 R 3 R 4 N + :YO 2 of the one or more tetraalkylammonium cation R 1 R 2 R 3 R 4 N + -containing compounds to YO 2 ranges from 0.1 to 0.5,
wherein a molar ratio R 5 R 6 R 7 R 8 N + :YO 2 of the one or more tetraalkylammonium cation R 5 R 6 R 7 R 8 N + -containing compounds to YO 2 ranges from 0.11 to 0.21,
wherein the one or more sources for X 2 O 3 comprises one or more compounds selected from the group consisting of aluminum tri (C 2 -C 3 )alkoxide, AlO(OH), Al(OH) 3 , aluminum chloride, aluminum sulfate, and mixtures of two or more thereof, and
wherein a molar ratio R 1 R 2 R 3 R 4 N + :R 5 R 6 R 7 R 8 N + of the one or more tetraalkylammonium cations R 1 R 2 R 3 R 4 N + to the one or more tetraalkylammonium cations R 5 R 6 R 7 R 8 N + in the mixture of the providing step ranges from 0.5 to 0.9.
2 . The process of claim 1 , wherein the one or more tetraalkylammonium cation R 1 R 2 R 3 R 4 N + -containing compounds comprise one or more compounds chosen from (C 1 -C 6 ) hydroxyalkyl-trimethyl ammonium compounds.
3 . The process of claim 1 , wherein Y is chosen from Si, Sn, Ti, Zr, Ge, and mixtures thereof.
4 . The process of claim 1 , wherein the mixture further comprises one or more solvents.
5 . The process of claim 1 , wherein the mixture is heated during the crystallizing.
6 . The process of claim 1 , wherein crystallizing the mixture is conducted under solvothermal conditions.
7 . The process of claim 1 , further comprising one or more of isolating the zeolitic material, washing the zeolitic material, drying the zeolitic material, calcining the zeolitic material, and ion-exchanging the zeolitic material.
8 . The process of claim 1 , wherein the mixture further comprises a seed crystal.
9 . The process of claim 1 , wherein, prior to the crystallizing, the mixture does not comprise zeolitic material having a CHA-type framework structure.