Patent ID: 11884632
Assignee: ZHEJIANG HENGYI PETROCHEMICAL RESEARCH INSTITUTE CO., LTD.
Field: Chemical engineering (Chemistry)
Classification: CPC C  B  Y | IPC B  C

Claim 7:
8. The method of claim 4, wherein a preparation method of the catalyst comprises the following steps:
(a-1) mixing ethyl orthosilicate, ethanol, a metal source, tetrapropylammonium hydroxide with water to obtain a colloid mixture; wherein the molar ratio of ethyl orthosilicate calculated by SiO2, ethanol, tetrapropylammonium hydroxide and water is 1: (4-25): (0.06-0.45): (6-100); the weight ratio of the ethyl orthosilicate calculated by SiO2 relative to the metal source calculated by the metal element is (10,000-200,000): 1;
(a-2) subjecting the colloid mixture to a two-stage crystallization with an ethanol-hydrothermal system under variable temperatures, wherein the conditions of the two-stage crystallization with an ethanol-hydrothermal system under variable temperatures comprise: crystallizing at 40-80° C. for 0.5-5 days, and then crystallizing at 80-130° C. for 0.5-5 days;
(a-3) concentrating the crystallization mother liquor obtained in step (a-2) to obtain a molecular sieve slurry;
(a-4) blending the molecular sieve slurry with a binder and pulping to obtain a molecular sieve-binder slurry; subjecting the molecular sieve-binder slurry to a mist spray forming, and then roasting; and
(a-5) contacting the roasted product of step (a-4) with an alkaline buffer solution of a nitrogen-containing compound, and subsequently carrying out drying.