Alkali treatment modifying method of Y-shaped molecular sieve

Abstract

The invention provides an alkali treatment modifying method of a Y-shaped molecular sieve, which comprises the following steps of: beating and uniformly mixing the Y-shaped molecular sieve and a strong alkali aqueous solution according to the mass ratio of the molecular sieve, a strong alkali and distilled water as (0.1-2): (0.05-2): (4-15), and carrying out alkali treatment for 0.1-24 hours at the temperature of 0-120 DEG C; compared with a parent Y-shaped molecular sieve, the obtained molecular sieve has the advanced performance of higher N2 adsorptive capacity, larger water absorbing capacity and the like. On the basis of modified treatment, the invention also provides a preparation method of an NH4 molecular sieve and an ultrastable Y-shaped molecular sieve, which comprises ammonium exchange treatment and hydrothermal ultrastable treatment implemented for a modified NaY molecular sieve after alkali treatment, and the obtained NH4 molecular sieve has lower metallic ion residues; an obtained USY molecular sieve has more abundant secondary holes while keeping high degree of crystallinity, thereby improving the catalytic activity of the USY molecular sieve.

Description

technical field

[0001] The present invention relates to a method for modifying Y-type molecular sieves, and more specifically to a method for modifying Y-type molecular sieves with an alkaline solution for desiliconization of the skeleton, and a related preparation method for modified Y-type molecular sieves, belonging to molecular sieves technology field. Background technique

[0002] Y-type molecular sieve is a microporous crystal material with regular skeleton structure. It is based on sodalite cages and arranged in three-dimensional space according to the structure of diamonds. Each sodalite cage uses its four six-membered rings in the direction of the vertices of the regular tetrahedron to connect with its adjacent sodalite cages. The gabions are connected to each other, thus forming the crystal structure of Y molecular sieve. Inside the crystal, a three-dimensional channel system is formed by crystal caves, crystal pores and channels. The internal structure of the sk...

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