Preparation method of core-shell magnetic titanium silicalite molecular sieve catalyst as well as product and application of core-shell magnetic titanium silicalite molecular sieve catalyst

Abstract

The invention discloses a preparation method of a core-shell magnetic titanium silicalite molecular sieve catalyst as well as a product and application of the core-shell magnetic titanium silicalite molecular sieve catalyst, and belongs to the technical field of molecular sieve catalysts. The preparation method comprises the following steps: dropwise adding a titanium source into an aqueous solution of a template agent, adding a magnetic medium, and carrying out crystallization treatment to obtain a magnetic core; mixing a silicon source, a titanium source, tetrapropylammonium hydroxide, water and isopropanol to obtain a precursor solution, adding the magnetic core, and performing secondary crystallization treatment and roasting to obtain a core-shell magnetic titanium silicalite molecular sieve; and adding acid for acid treatment, filtering, washing, drying and roasting to obtain the core-shell magnetic titanium silicalite molecular sieve catalyst. By introducing the magnetic core, the technical purposes of easy separation and easy recovery are achieved; the content of framework titanium is increased through high-temperature and high-pressure acid treatment, the technical purpose of efficiently catalyzing one-step synthesis of ethylene glycol from ethylene is achieved, and wide application value is achieved.

Description

technical field [0001] The invention relates to the technical field of molecular sieve catalysts, in particular to a preparation method of a core-shell magnetic titanium-silicon molecular sieve catalyst and its product and application. Background technique [0002] Ethylene glycol is an important chemical raw material, mainly used in the production of polyester, antifreeze, refrigerant, surfactant, lubricant, plasticizer and other fine chemicals. The current industrial production of ethylene glycol includes petroleum route and natural gas route, but because the quality of ethylene glycol produced by the natural gas route is slightly worse than that of the petroleum route, the methods for industrial production of ethylene glycol at home and abroad are still mainly It is a petroleum route, that is, ethylene glycol is synthesized in two steps using ethylene as a raw material: first, ethylene oxide is epoxidized to produce ethylene oxide, and second, ethylene oxide is hydrated t...

AI Technical Summary

Problems solved by technology

The catalyst in TS-1 molecular sieve is the framework titanium, and the non-skeleton titanium not only has no catalytic activity, but also covers the titanium active sites, resulting in a decrease in the crystallinity, specific surface area, and pore volume of the molecular sieve, which in turn affects the oxidation and hydration of ethylene. Catalytic activity

In addition, the titanium-silicon molecular sieve powder catalyst prepared by the classical synthesis method usually has a small particle size, and it is difficult to recycle and reuse after the reaction

The patent CN110102340A directly introduces the magnetic core into the crystallization precursor solution, and through integration, a composite material of titanium silicon molecular sieve and magnetic core is obtained, which realizes the rapid separation of the catalyst, and the preparation method is simple and the cost is low, but the magnetic core is directly The introduction of titanium-silicon molecular sieves will inevitably destroy the original framework of titanium-silicon molecular sieves, resulting in loss of catalyst activity

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