Crystalline silicate particle having an aluminum-containing outer shell
AssigneeChevron Research Company
InventorStephen J. Miller
Life of this patent
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Abstract
Crystalline silicate particles having an aluminum-containing isostructural outer shell. The particles are prepared by first crystallizing crystalline silicate particles from a first reaction medium and thereafter crystallizing an isostructural outer shell onto said crystalline silicate particles from a reaction medium containing an increased source of aluminum.
Claims20
A particle, comprising an inner portion and an outer portion disposed as a shell around said inner portion wherein said outer portion has the same crystal structure as said inner portion, said inner portion comprising an intermediate pore size crystalline silicate having a silica:alumina mole ratio greater than about 200:1, and said outer portion having a silica:alumina mole ratio of less than about 100:1 and wherein said particle is prepared by a process comprising:
- (1) initiating crystallization in a crystallization medium substantially free of aluminum to produce the intermediate pore size crystalline silicate;
- (2) adding a source of aluminum to said crystallization medium;
- and
- (3) crystallizing onto said crystalline silicate the isostructural outer portion which comprises alumina.
A particle, comprising an inner portion and an outer portion disposed as a shell around said inner portion wherein said outer portion has the same crystal structure as said inner portion, said inner portion comprising an intermediate pore size crystalline silicate having a silica:alumina mole ratio greater than about 200:1, and said outer portion having a silica:alumina mole ratio of less than about 100:1 and wherein said particle is prepared by a process comprising:
- (1) crystallizing the intermediate pore size crystalline silicate from a first reaction medium substantially free of aluminum;
- (2) removing said crystalline silicate from said first reaction medium;
- (3) adding said crystalline silicate to a second reaction medium comprising sources of aluminum, and
- (4) crystallizing the isostructural, alumina containing outer layer onto said crystalline silicate.
A process for preparing a particle, comprising an inner portion and an outer portion disposed as a shell around said inner portion wherein said outer portion has the same crystal structure as said inner portion, said inner portion comprising an intermediate pore size crystalline silicate having a silica:alumina mole ratio greater than about 200:1, and said outer portion having a silica:alumina mole ratio of less than about 100:1, comprising:
- (1) initiating crystallization in a crystallization medium substantially free of aluminum to produce the intermediate pore size crystalline silicate;
- (2) adding a source of aluminum to said crystallization medium;
- and
- (3) crystallizing onto said crystalline silicate the isostructural outer portion which comprises alumina.
A process for preparing a particle, comprising an inner portion and an outer portion disposed as a shell around said inner portion wherein said outer portion has the same crystal structure as said inner portion, said inner portion comprising an intermediate pore size crystalline silicate having a silica:alumina mole ratio greater than about 200:1, and said outer portion having a silica:alumina mole ratio of less than about 100:1, comprising:
- (1) crystallizing the intermediate pore size crystalline silicate from a first reaction medium substantially free of aluminum;
- (2) removing said crystalline silicate from said first reaction medium;
- (3) adding said crystalline silicate to a second reaction medium comprising sources of aluminum, and
- (4) crystallizing the isostructural, alumina containing outer layer onto said crystalline silicate.
Dependencies are inferred from the claim text.