Hierarchical structure ZSM-5 molecular sieve containing lanthanum and nickel or/and zinc , and preparation method and application thereof

Abstract

The invention relates to a hierarchical structure ZSM-5 molecular sieve containing lanthanum and nickel or / and zinc, a preparation method thereof, and application of the hierarchical structure ZSM-5 molecular sieve in catalytic gasoline olefin reduction. The molecular sieve is ZSM-5 zeolite which is obtained by adopting a hydrothermal synthesis method and has a silicon-aluminum atomic ratio of 10-50, and pores in the zeolite contain lanthanum and zinc or / and nickel; the hierarchical structure ZSM-5 molecular sieve has a mesoporous structure formed by secondary accumulation of crystal grains of the molecular sieve, the volume of mesopores is not less than 0.09 cm<3> / g, the specific surface area is greater than 200 cm<2> / g, the size of primary particles of the molecular sieve is about 300 nm to 2 [mu]m, and the size of secondary accumulation particles is 2 [mu]m to 8 [mu]m. The hierarchical structure ZSM-5 molecular sieve containing lanthanum and nickel or / and zinc has high acid content and L acid / B acid ratio, and more mesoporous structures improve the diffusion rate of macromolecular reactants or products and enhance the carbon containing capacity of the catalyst, so the hierarchical structure ZSM-5 molecular sieve has high desulfurization and olefin reduction-octane number recovery activity and long-period stability in catalytic gasoline olefin reduction-modification reaction.

Description

technical field [0001] The invention belongs to the technical field of catalytic materials and catalytic chemistry, and specifically relates to a hydrothermal synthesis method and application of a gasoline-reduced olefin-modified multi-stage structure ZSM-5 zeolite molecular sieve. Background technique [0002] Due to its unique pore structure, acid properties, high hydrothermal stability, and lipophilic and hydrophobic properties, ZSM-5 molecular sieve itself is a good catalyst and is often used as a solid acid catalyst. It is widely used in alkylation, catalytic cracking, alcohol, etc. reactions such as dehydration. At the same time, because of its high specific surface area and excellent ion exchange performance, it is also an excellent carrier for catalytically active metal ions or metal compounds. ZSM-5 molecular sieve-loaded iron, silver, copper and other catalysts are used in the oxidation of benzene and nitrogen oxides. It exhibits excellent catalytic performance in...

AI Technical Summary

Problems solved by technology

This is mainly because ZSM-5 molecular sieve with low silicon-aluminum ratio is mainly used in olefin aromatization reaction, and it is very difficult to synthesize pure ZSM-5 zeolite molecular sieve with low silicon-aluminum ratio by liquid phase hydrothermal synthesis

If one or more metal salts are added, the gel concentration will be further increased, making the synthesis more difficult

Therefore, although the hydrothermal synthesis of zinc, nickel, lanthanum and low-silicon ZSM-5 molecular sieves with a multi-level structure is of great significance, the synthesis is more challenging, and there have been no relevant patent reports so far.

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