Ternary composite metal oxide solid alkali catalyst and preparation method and application thereof

Abstract

The invention provides a ternary composite metal oxide solid alkali catalyst and a preparation method and application thereof. According to the method, urea is taken as a precipitant, a hydrothermal method is adopted for preparing a magnalium hydrotalcite precursor, the magnalium hydrotalcite precursor is dispersed in a cerate solution, the mixture and a sodium borohydride solution are put in a colloid mill, stirred for a reaction and transferred into a hydrothermal reactor, and hydrothermal crystallization is conducted, so that CeO2 nanoparticles with rich defect sites and alkaline sites areuniformly deposited on the surface of an MgAl-LDH piece structure; a CeO2/MgAl-LDH composite precursor is obtained, and after roasting treatment, the ternary composite metal oxide solid alkali catalyst CeO2/MgO-Al2O3 is obtained. The CeO2 nanoparticles in the catalyst are uniformly dispersed on the surface of an MgO-Al2O3 composite oxide in a piece shape, the size of the particles is 20-30 nm, andthe mass percentage of CeO2 is 3-25%; the specific surface area of the catalyst is 80-130 m2/g. The catalyst is used for the reaction for preparing glycerinum carbonic ester through the direct reaction of glycerinum and CO2, the conversion rate of the catalyst is 84.4-92.1%, and the selectivity of the catalyst is 92.3-93.6%.

Description

technical field [0001] The invention belongs to the technical field of catalyst preparation, in particular to a method for preparing a ternary composite metal oxide solid base catalyst, which is suitable for CO 2 and the selective catalytic conversion of glycerol to glycerol carbonate. Background technique [0002] With the development of modern industry, the consumption of fossil fuels produces a large amount of CO 2 , has seriously exceeded the capacity and scope of the natural carbon cycle. High concentration of CO 2 The resulting greenhouse effect is increasingly affecting human production and life. How to reduce CO 2 emissions and CO 2 Converting to high value-added fine chemicals and fuels is currently a difficult problem faced by all countries, and it is also a research difficulty and hot spot for scientific researchers. [0003] In order to reduce environmental pollution, reduce carbon emissions, and achieve green and sustainable development, countries all over...

AI Technical Summary

Problems solved by technology

In the literature Applied Catalysis A: General, 2016, 513, 9-18, Liu et al. 2 As catalyst, 2-cyanopyridine was used as dehydrating agent, glycerol and CO 2 Glycerol carbonate is prepared as the reaction raw material, but the yield of glycerol carbonate is relatively low, only 78%

CeO 2 Nanocatalysts catalyze glycerol and CO 2 The reaction of preparing glycerol carbonate often faces problems such as low catalyst activity and easy agglomeration and deactivation

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