Methods to produce molecular sieves with LTA topology and compositions derived therefrom
AssigneeCalifornia Institute of Technology
InventorsBen W. Boal, Mark E. Davis, Joel E. Schmidt
Life of this patent
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Abstract
The present disclosure is directed to processing for preparing crystalline pure-silica and heteroatom-substituted LTA frameworks in fluoride media using a simple organic structure-directing agent (OSDA), having a structure of Formula (I): where substituents R1 to R9 are defined herein. Aluminosilicate LTA is an active catalyst for the methanol to olefins reaction with higher product selectivities to butenes as well as C5 and C6 products than the commercialized catalysts. Titanosilicate LTA is an active catalyst for the epoxidation of allyl alcohol using aqueous H2O2.
Claims30
A process for comprising hydrothermally treating an aqueous composition comprising:
- (a) a source of a silicon oxide;
- (b) an optional source of an aluminum oxide;
- (c) an optional source of a germanium oxide;
- (d) an optional source of a titanium oxide;
- (e) an optional source of one or more of a boron oxide, gallium oxide, hafnium oxide, iron oxide, tin oxide, indium oxide, vanadium oxide, zinc oxide, zirconium oxide, or combination or mixture thereof;
- (f) a mineralizing agent;
- and
- (g) an organic structure directing agent (OSDA) comprising a substituted benzyl-3H-imidazol-1-ium cation of Formula (I):
- and optionally a tetramethylammonium salt, under conditions effective to crystallize a crystalline microporous silicate solid of LTA topology;
- wherein
- R1, R2, and R7 are independently C1-6 alkyl;
- R3, R4, R5, R6, R8, and R9 are independently H or C1-3 alkyl;
- and
- the substituted benzyl-3H-imidazol-1-ium cation has an associated bromide, chloride, fluoride, iodide, nitrate, or hydroxide anion.
A crystalline microporous silicate solid of LTA topology, prepared by the process of claimed 1, containing within its pores an OSDA comprising a substituted benzyl-3H-imidazol-1-ium cation of Formula (I):
- wherein
- R1, R2, and R7 are independently C1-6 alkyl;
- R3, R4, R5, R6, R8, and R9 are independently H or C1-3 alkyl.
The crystalline microporous silicate solid of LTA topology of claimed 15, wherein the solid is:
- (a) a pure-silicate;
- (b) an aluminosilicate;
- (c) a germanosilicate;
- or
- (d) a titanosilicate.
A composition comprising:
- (a) a source of a silicon oxide;
- (b) an optional source of an aluminum oxide;
- (c) an optional source of a germanium oxide;
- (d) an optional source of a titanium oxide;
- (e) an optional source of one or more of a boron oxide, gallium oxide, hafnium oxide, iron oxide, tin oxide, titanium oxide, indium oxide, vanadium oxide, zinc oxide, zirconium oxide, or combination or mixture thereof;
- (f) a mineralizing agent;
- and
- (g) an organic structure directing agent (OSDA) comprising a substituted benzyl-3H-imidazol-1-ium cation of Formula (I):
- and
- (h) a compositionally consistent crystalline microporous silicate solid of LTA topology having the OSDA occluded in its micropores;
- wherein
- R1, R2, and R7 are independently C1-6 alkyl;
- R3, R4, R5, R6, R8, and R9 are independently H or C1-3 alkyl;
- and
- the substituted benzyl-3H-imidazol-1-ium cation has an associated bromide, chloride, fluoride, iodide, nitrate, or hydroxide anion.
Dependencies are inferred from the claim text.