Preparation method of ZnO-ZrO2@SAPO-34 core-shell catalyst

Abstract

The invention discloses a preparation method of a ZnO-ZrO2@SAPO-34 core-shell catalyst. The preparation method comprises the following steps: preparing ZnO-ZrO2 powder; according to a molar ratio of raw materials, namely Al2O3, P2O5, SiO2, MOR (morpholine) and H2O, of 1.0:0.8:0.6:2.5:80, sequentially adding pseudoboehmite, tetraethyl orthosilicate and a templating agent morpholine into an orthophosphoric acid solution while stirring, continuously stirring uniformly, stirring and aging at room temperature for 24h to form a sol system, adding the ZnO-ZrO2 powder into the system according to a core-shell mass ratio of ZnO-ZrO2 to SAPO-34 of 1:4 to 4:1, continuing stirring uniformly, then transferring to a reaction kettle, performing hydrothermal crystallization at 190-210 DEG C for 24-48h, cooling, filtering, washing by using deionized water till a neutral state, drying at 105 DEG C for 6h, and roasting at 500-600 DEG C for 3h to obtain the ZnO-ZrO2@SAPO-34 core-shell catalyst. The catalyst prepared by the preparation method provided by the invention can simultaneously increase the carbon dioxide conversion rate and the low-carbon olefin selectivity in a two-step technology in which the low-carbon olefin is prepared from methanol through CO2 hydrogenation.

Description

Technical field [0001] The invention belongs to the technical field of chemical engineering, and specifically relates to a ZnO-ZrO 2 @SAPO-34 Preparation method of core-shell structure catalyst. Background technique [0002] Zinc Zirconium (ZnO-ZrO 2 ) The two-component catalyst is CO 2 Catalytic hydrogenation process for methanol synthesis is a type of metal oxide catalyst with strong anti-sintering stability and sulfur resistance, and good effect. SAPO-34 molecular sieve is made of SiO 4 , AlO 4 And PO 4 The microporous silica-aluminophosphate molecular sieve with three kinds of tetrahedral units staggered into a three-dimensional cross-pore structure is widely used because of its rich and adjustable B acid properties, high specific surface area and unique shape-selective function of microporous products. Methanol catalytic cracking process to produce light olefins (MTO). According to this, a dual-functional core-shell catalyst was prepared by coupling metal oxides and acid m...

AI Technical Summary

Problems solved by technology

However, the active components of existing composite catalysts are randomly distributed, and the structure only provides an open reaction environment. More importantly, the distribution structure with traditional nano-copper particles as the active component has extremely poor anti-sintering stability and cannot effectively solve the problem of CO 2 CO in the two-step process of hydrogenation and methanol to light olefins 2 The hydrogenation synthesis of methanol process and methanol catalytic conversion to light olefins process require different reaction formation and dissociation conversion environmental conditions, resulting in the poor catalytic effect of existing composite catalysts