Magnetic titanium silicon molecular sieve with compact protective layer and its application

Abstract

The invention discloses a magnetic titanium silicon molecular sieve with a compact protective layer and its application. The preparation method of the magnetic titanium silicon molecular sieve consists of the steps of: (1) preparing a ferric salt or ferrous salt water solution, performing a reflux reaction to obtain Fe nanoparticles; (2) adding the Fe nanoparticles prepared in step (1) into an isopropyl alcohol solution containing NH3.H2O and water, stirring them uniformly, then adding tetraethyl orthosilicate and leaving them to react completely, then carrying out separation to obtain solid particles, and conducting roasting to obtain Fe / SiO2 nanoparticles with a compact SiO2 layer; (3) mixing the Fe / SiO2 nanoparticles with the compact SiO2 layer with a glucose water solution, performing crystallization to obtain carbon-coated Fe / SiO2 / C nanoparticles; and (4) preparing a TS-1 molecular sieve mother liquor, mixing the carbon-coated Fe / SiO2 / C nanoparticles with the TS-1 molecular sieve mother liquor, and carrying out crystallization and roasting, thus obtaining the magnetic titanium silicon molecular sieve with a compact protective layer. The magnetic titanium silicon molecular sieve can be used as a catalyst in preparation of epichlorohydrin by epoxidation of allyl chloride and hydrogen peroxide, and has good catalytic properties.

Description

(1) Technical field [0001] The invention relates to a kind of dense SiO 2 Layered magnetic titanium silicon molecular sieve and its application, especially as a catalyst in the reaction of epoxidation of chloropropene to epichlorohydrin. (2) Technical background [0002] Epichlorohydrin (ECH for short) is an important organic synthesis intermediate, mainly used in the production of epoxy resin, synthetic glycerin, chlorohydrin rubber and paper wet strength agent, etc., and a small amount is used to prepare epoxypropyl Ethers and esters; can also be used in nitroglycerin explosives, glass fiber reinforced plastics, electrical insulation products, surfactants, medicines, pesticides, coatings, ion exchange resins, plasticizers and other products; made from epichlorohydrin Epoxy resins are widely used in anti-corrosion, coatings, adhesives, composite materials, civil construction and electronic laminates, and are known as "the most valuable organic intermediates". [0003] In ...

AI Technical Summary

Problems solved by technology

Disadvantages are: severe equipment corrosion caused by raw material chlorine, high requirements for propylene purity and reactor material, high energy consumption, high chlorine consumption, many by-products, and low product yield

The main disadvantages are: the process is long, the life of the catalyst is short, stainless steel materials resistant to acetic acid corrosion are required, the explosion of the mixed gas in the allyl alcohol unit must be prevented, and the investment is relatively high

CN102139226A reports a TS-1 magnetic titanium-containing molecular sieve. Although the molecular sieve is easy to recycle and separate due to the magnetic effect, the small molecule reactant is easy to pass through the pores of the molecular sieve and react with the magnetic nucleus in the heterogeneous reaction, which affects the conversion rate and product of the reaction. yield, etc.

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