Fluorine-containing high-silicon Y molecular sieve and preparation method thereof

Abstract

The invention discloses a fluorine-containing high-silicon Y molecular sieve and a preparation method thereof, and belongs to the field of molecular sieve synthesis. The anhydrous chemical compositionof the fluorine-containing high-silicon Y molecular sieve is hF.kM.mR1. NR2. (SixAly) O2, and the silica-alumina ratio of the fluorine-containing high-silicon Y molecular sieve is 25-100. The methodcomprises the following steps: a) mixing raw materials containing an aluminum source, a silicon source, an alkali metal source, a fluorine source, an organic template agent R2 and water to obtain initial gel, then adding a guiding agent or a silicon-aluminum molecular sieve seed crystal, and stirring to obtain synthetic gel; b) dewatering the synthetic gel to obtain a dry powder mixture; and c) crystallizing the dry powder mixture. According to the method disclosed by the invention, the fluorine-containing high silicon Y molecular sieve has characteristics of high silica-alumina ratio, low alkali metal content and easy ion exchange, and the preparation method has characteristics of rapid crystallization rate, simple process, and easy large-scale industrial production.

Description

technical field [0001] This application relates to a fluorine-containing high-silicon Y molecular sieve and its preparation method, and in particular to a synthesis of fluorine-containing high-silicon Y molecular sieve under ultra-low water by introducing an organic template into the synthetic gel system and adding a directing agent or seed crystal. The method for Y molecular sieve belongs to the field of molecular sieve synthesis. Background technique [0002] Y molecular sieve is a silica-alumina molecular sieve with FAU topology, which is mainly used in fluid catalytic cracking (FCC), and is currently the most used molecular sieve material. The silicon-aluminum ratio of Y molecular sieve plays a decisive role in its catalytic performance, and the higher the silicon-aluminum ratio, the better the catalytic activity and stability. At present, the high-silicon Y molecular sieves used in industry are mainly obtained through chemical / physical dealumination, etc. This post-tre...

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Problems solved by technology

[0006] In 1990, French Delprato et al. (Zeolites, 1990,10(6):546-552) synthesized FAU molecular sieves with a cubic structure for the first time using crown ethers as templates. The highest value that can be achieved by the method, but the expensive and highly toxic crown ether limits its industrial application

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