Novel method for synthesizing cubic phase interpose porus molecular sieve material

Abstract

A novel method of synthesis of cubic mesoporous molecular sieve materials is provided, which relates to the synthetic method of the cubic (Ia3d) mesoporous molecular sieve materials. The invention aims to introduce the acidity and improve the stability. The quarternary ammonium cationics CmTMA+, the quarternary ammonium cationics Cn-3-1 with bipolar head, the boric acid, the water, the sodium hydroxide and the silicon source are mixed according to the mol ratio of 0.03 to 0.05 : 0.03 to 0.06 : 0.003 to 0.05 : 100 to 150 : 0 to 0.4 : 1; the silicon source is calculated based on the SiO2 volume and the pH value is adjusted to 9 to 10; then chemical regulators having mol ratio of 0.03 to 0.06 with the SiO2 volume of the silicon source are added into the mixture and is crystallized for 48 to 72 hours under 373K; the pH value is adjusted between 9 and 10 every 12 hours; the cubic mesoporous molecular sieve materials are gained through separation, washing and drying after completing the crystallization. The prepared mesoporous materials are characterized by high degree of order, uniform mesoporous arrangement, high specific area, strong acidity and high stability.

Description

technical field [0001] The invention relates to a synthesis method of mesoporous molecular sieves, in particular to a synthesis method of cubic phase (Ia3d) mesoporous molecular sieve materials. Background technique [0002] In the 1990s Mobil Company Beck and Kresge et al (Beck J.S., Vartuli J.C., Roth W.J. et al, JACS, 1992, 114 (27), 10834-10843; Kresge C.T., Leonowicz M Z, Roth W.J. et al, Nature, 1992, 359 (6397), 710-712) used cationic surfactant (C n h 2n+1 Me 3 N + , n=8-16) as template agent, hydrothermal crystallization (373-423K) silicate or aluminate gel is synthesized in one step to produce a series of mesoporous materials with regular pore structure and narrow pore size distribution, denoted as M41S, Includes MCM-41 (hexagonal), MCM-48 (cubic), layered materials and cubic octamers. Among them, MCM-41 is the most representative member of this series of mesoporous materials, which has a uniform and regular one-dimensional hexagonal channel structure. The MC...

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Problems solved by technology

Unfortunately, the disadvantages of poor stability and poor acidity, which hinder the wide application of mesoporous materials in industrial production, have not been fundamentally resolved.

The synthesis of MCM-48 at room temperature eased the synthesis conditions, but the low hydrothermal synthesis temperature caused the incomplete polymerization of the mesoporous molecular sieve wall and produced more silanol groups. This is the mesoporous molecular sieve including MCM-48. One of the main reasons for the poor hydrothermal stability of materials

Although post-synthesis hydrothermal treatment can increase the degree of polymerization of the pore wall to a certain extent and improve the stability of MCM-48, compared with Beta and ZSM-5, which are widely used in the petrochemical industry, the stability is still low. , so further improving the thermal / hydrothermal stability of mesoporous molecular sieves is still a research goal pursued by people.

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