A family of new crystalline molecular sieves designated SSZ-91 is disclosed, as are methods for making SSZ-91 and uses for SSZ-91. Molecular sieve SSZ-91 is structurally similar to sieves falling within the ZSM-48 family of molecular sieves, and is characterized as: (1) having a low degree of faulting, (2) a low aspect ratio that inhibits hydrocracking as compared to conventional ZSM-48 materials having an aspect ratio of greater than 8, and (3) is substantially phase pure.

A family of new crystalline molecular sieves designated SSZ-91 is disclosed, as are methods for making SSZ-91 and uses for SSZ-91. Molecular sieve SSZ-91 is structurally similar to sieves falling within the ZSM-48 family of molecular sieves, and is characterized as: (1) having a low degree of faulting, (2) a low aspect ratio that inhibits hydrocracking as compared to conventional ZSM-48 materials having an aspect ratio of greater than 8, and (3) is substantially phase pure.

An object of the present invention is to provide an AFX zeolite having a novel structure. An AFX zeolite having a lattice spacing d of a (004) plane being not less than 4.84 Å and not greater than 5.00 Å, and a molar ratio of silica to alumina being not less than 10 and not higher than 32. Such an AFX zeolite can be produced by a production method comprising a crystallization step of crystallizing a composition at a temperature of not lower than 160° C.; the composition containing a silicon source, an aluminum source, a 1,3-di(1-adamantyl)imidazolium cation, and an alkali metal; a molar ratio of hydroxide ions to silica being less than 0.25 or a molar ratio of silica to alumina being not higher than 27; and a molar ratio of the 1,3-di(1-adamantyl)imidazolium cation to silica being less than 0.20.

An object of the present invention is to provide an AFX zeolite having a novel structure. An AFX zeolite having a lattice spacing d of a (004) plane being not less than 4.84 Å and not greater than 5.00 Å, and a molar ratio of silica to alumina being not less than 10 and not higher than 32. Such an AFX zeolite can be produced by a production method comprising a crystallization step of crystallizing a composition at a temperature of not lower than 160° C.; the composition containing a silicon source, an aluminum source, a 1,3-di(1-adamantyl)imidazolium cation, and an alkali metal; a molar ratio of hydroxide ions to silica being less than 0.25 or a molar ratio of silica to alumina being not higher than 27; and a molar ratio of the 1,3-di(1-adamantyl)imidazolium cation to silica being less than 0.20.

An AFX framework type zeolite having a SiO.sub.2/Al.sub.2O.sub.3 molar ratio of greater than 50 is disclosed. The high-silica AFX framework type zeolite is synthesized from a reaction mixture having high silica and low hydroxide concentrations in the presence of an organic structure directing agent comprising 1,3-bis(1-adamantyl)imidazolium cations.

An AFX framework type zeolite having a SiO.sub.2/Al.sub.2O.sub.3 molar ratio of greater than 50 is disclosed. The high-silica AFX framework type zeolite is synthesized from a reaction mixture having high silica and low hydroxide concentrations in the presence of an organic structure directing agent comprising 1,3-bis(1-adamantyl)imidazolium cations.

The present invention relates to the technical field of molecular sieves, in particular to a single-crystal hierarchical pore HZSM-5 molecular sieve and an environment-friendly preparation method thereof. The environment-friendly preparation method of the single-crystal hierarchical pore HZSM-5 molecular sieve includes the following steps: preparing a sample by a hydrothermal method with nitrogen-free polyketal as a template agent; and conducting acid treatment on the obtained sample to remove the template agent and to obtain the single-crystal hierarchical pore HZSM-5 molecular sieve. A mesopore diameter of the single-crystal hierarchical pore HZSM-5 molecular sieve is concentrated at 10 to 40 nm, a crystal grain size thereof is 30 to 500 nm, a specific surface area thereof is 360 to 450 m.sup.2/g, and a pore volume thereof is 0.32 to 0.42 cm.sup.3/g. The present application can not only solve the problems such as collapse of a molecular sieve structure caused by high-temperature roasting, emission of harmful gases and non-recyclability of the template agent, but also can shorten a preparation process of the HZSM-5 molecular sieve and reduce energy consumption and material consumption of the process; and the synthesized HZSM-5 molecular sieve has single-crystal hierarchical pores, and has the advantages of hydrothermal stability, high specific surface area, high pore volume and the like.

The present invention relates to the technical field of molecular sieves, in particular to a neutral polymer-oriented hierarchical pore Beta molecular sieve and an environment-friendly preparation method thereof. The environment-friendly preparation method of the neutral polymer-oriented hierarchical pore Beta molecular sieve includes the following steps: preparing a sample by a hydrothermal method with nitrogen-free polyketal as a template agent; and conducting acid treatment on the obtained sample to remove the template agent and to obtain the hierarchical pore Beta molecular sieve. The hierarchical pore Beta molecular sieve is a nano-mesoporous molecular sieve, a mesopore diameter thereof is concentrated at 10 to 20 nm, a crystal grain size thereof is 30 to 120 nm, a specific surface area thereof is 700 to 820 m.sup.2/g, and a pore volume thereof is 0.75 to 0.92 cm.sup.3/g. The present application can solve the problems such as collapse of a molecular sieve structure caused by high-temperature roasting, emission of harmful gases and non-recyclability of the template agent. Moreover, the prepared Beta molecular sieve is a hierarchical pore molecular sieve, and has the advantages of nano-single crystal structure, high specific surface area, high pore volume and the like.

A method is disclosed for synthesizing molecular sieve SSZ-63 using 1-(decahydronaphthalen-2-yl)-1-methylpyrrolidinium cations as a structure directing agent.

A method is disclosed for synthesizing molecular sieve SSZ-63 using 1-(decahydronaphthalen-2-yl)-1-methylpyrrolidinium cations as a structure directing agent.