ZrO2-SiO2 compound oxides, its preparation method and application

Abstract

A ZrO2 - SiO2 composite oxides includes 85~98 wt% ZrO2 and 2-15wt% SiO2, the most probable aperture is 3-8nm and at least diameter of 90% hole is 3~8 nm, hole structure is the cylinder-shaped hollow structure; and the specific surface area of BET is 120 to 150 m 2/g, the index H0 of acid strength Hammet is -8.4--5.6. Said preparation method of ZrO2 - SiO2 includes: adding silicon-containing compound and surface activator into zirconium-containing compound solution under the condition of continuous stirring to form mixture, then adding alkaline solution into said mixture under the condition of continuous stirring to form sol, after ageing, washing and filtering the sol and preparing gel, then producing the ZrO2 - SiO2 solid after drying and roasting gel. The activator using the composite oxide as carrier is used for transfer reaction of pseudocumene and toluene alkyl group and has higher pseudocumene conversion rate and better dimethylbenzene selective.

Description

technical field [0001] The invention relates to a composite oxide and its preparation method and application. Specifically, a ZrO 2 -SiO 2 Composite oxide, its preparation method and its application in aromatic hydrocarbon transalkylation reaction. Background technique [0002] In the field of catalysis, how to prepare high-activity, high-selectivity, and long-life high-efficiency catalysts has always been a topic of concern. The development of new catalytic materials is the key to solve this problem. The preparation of catalysts by using catalytic materials with large specific surface area, certain acid-alkaline or / and certain oxidation-reduction properties, stable and special pore structure, and specific pore size can improve the reactivity and selectivity of the catalyst and improve the use of the catalyst life, which is conducive to the regeneration of the catalyst. [0003] Zeolite molecular sieves are an important class of catalytic materials. They have the charac...

AI Technical Summary

Problems solved by technology

However, at present, whether it is a natural zeolite molecular sieve or a synthetic zeolite molecular sieve, its pore diameter is less than 1.5 nm, and its hydrothermal stability is relatively poor.

This limits the use of zeolite molecular sieves to catalytic reactions involving small molecules and relatively mild hydrothermal conditions, but not suitable for catalytic reactions involving organic macromolecules or harsh hydrothermal conditions.

Images