Molecular sieves and related methods and structure directing agents

#The present disclosure relates to molecular sieves and related methods and structure directing agents.

#Molecular sieves are a class of important materials used in the chemical industry for processes such as gas stream purification and hydrocarbon conversion processes. Molecular sieves are porous solids having interconnected pores of same or different sizes. Molecular sieves typically have a one-, two- or three-dimensional crystalline pore structure having pores of one or more molecular dimensions that selectively adsorb molecules that can enter the pores, and exclude those molecules that are too large. The pore size, pore shape, interstitial spacing or channels, composition, crystal morphology and structure are a few characteristics of molecular sieves that determine their use in various hydrocarbon adsorption and conversion processes.

#Molecular sieves and related methods and structure directing agents are herein described. In particular, in some embodiments molecular sieves are described that are obtainable by a method for preparing various molecular sieves in a hydroxide media, that uses structure directing agents, such as various imidazolium cations.

#FIG. 1 illustrates an XRD pattern for one as-synthesized product according to an embodiment of the present disclosure.

#FIG. 2 illustrates an XRD pattern for one calcined product according to an embodiment of the present disclosure.

#FIG. 3 illustrates an XRD pattern for another as-synthesized product according to an embodiment of the present disclosure.

#Molecular sieves and related methods and structure directing agents are herein described.

#The term “molecular sieve” indicates a porous solid having interconnected pores of same or different sizes, and includes (a) intermediate and (b) final or target molecular sieves and molecular sieves produced by (1) direct synthesis or (2) post-crystallization treatment (secondary synthesis). Secondary synthesis techniques allow for the synthesis of a target material having a higher Si:Al ratio from an intermediate material by acid leaching or other similar dealumination methods.

#Molecular sieves particularly useful in industries such as petroleum and petrochemical industries are the zeolites. A zeolite is an aluminosilicate having an open framework structure sharing the oxygen atoms of [SiO4] and [AlO4] tetrahedra or octahedra. Mobile extra framework cations reside in the pores for balancing charges along the zeolite framework. These charges are a result of substitution of a tetrahedral framework cation (e.g. Si4+) with a trivalent or pentavalent cation. Extra framework cations counter-balance these charges preserving the electroneutrality of the framework, and these cations are exchangeable with other cations and/or protons.