Synthesis of silicoaluminophosphate molecular sieves
AssigneeExxonMobil Chemical Patents Inc.
InventorsMachteld Mertens, An Verberckmoes
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Abstract
In a method of synthesizing a silicoaluminophosphate molecular sieve comprising a CHA framework type material, an AEI framework type material, or a material comprising at least one intergrown phase of an AEI framework type and a CHA framework type, the amount of alkali metal present in said synthesis mixture is controlled so as to reduce the crystal size of the molecular sieve and/or to increase the AEI character of the intergrown phase.
Claims38
A method of synthesizing a silicoaluminophosphate molecular sieve comprising a CHA framework type material, an AEI framework type material, or a material comprising at least one intergrown phase of an AEI framework type and a CHA framework type, the method comprising:
- (a) preparing a synthesis mixture comprising water, an organic directing agent and sources of phosphorus, alumina and silica, wherein the total amount of alkali metal present in said synthesis mixture is from about 0.08 to about 0.90 g/mole alumina;
- (b) heating said synthesis mixture to a crystallization temperature of between about 100° C. and about 300° C.;
- and
- (c) recovering said molecular sieve.
A method of synthesizing a silicoaluminophosphate molecular sieve comprising at least one intergrown phase of a CHA framework type and an AEI framework type, wherein said at least one intergrown phase has an AEI/CHA ratio of from about 5/95 to about 40/60 as determined by DIFFaX analysis, the method comprising:
- (a) preparing a synthesis mixture comprising water, an organic directing agent and sources of phosphorus, aluminum and silicon, wherein the total amount of alkali metal present in said synthesis mixture is from about 0.08 to about 0.90 g/mole alumina and said mixture has a molar composition within the following ranges:
- P2O5:Al2O3 from about 0.6 to about 1.2,
- SiO2:Al2O3 from about 0.12 to about 0.20,
- H2O:Al2O3 from about 25 to about 50,
- (b) heating said mixture under agitation to a crystallization temperature of between about 100° C. and about 300° C.;
- and
- (c) recovering said molecular sieve.
A method of synthesizing a silicoaluminophosphate molecular sieve comprising at least one intergrown phase of a CHA framework type material and an AEI framework type material, wherein said at least one intergrown phase comprises at least 50 wt % of said AEI framework type material as determined by DIFFaX analysis, the method comprising:
- (a) preparing a synthesis mixture comprising water, an organic directing agent and sources of phosphorus, alumina and silica, wherein the total amount of alkali metal present in said synthesis mixture is at least 1.00 g/mole of alumina and said mixture has a molar composition within the following ranges:
- P2O5:Al2O3 from about 0.6 to about 1.2,
- SiO2:Al2O3 from about 0.005 to about 0.15,
- H2O:Al2O3 from about 10 to about 50,
- (b) heating said mixture under agitation to a crystallization temperature of between about 100° C. and about 300° C.;
- and
- (c) recovering said molecular sieve.
Dependencies are inferred from the claim text.