Method for preparing nano-Ce-Magnesium coumpoud oxide

Abstract

The present invention relates to two methods for preparing nanometre Ce-Mg composite oxide, which belongs to the superfine Ce-Mg composite oxide powder preparation field. Sol gel method has the reaction material of cerium nitrate hexahydrate and basic magnesium carbonate, and has a complexing agent of malic acid, wherein the cerous nitrate and the basic magnesium carbonate are dissolved in water respectively and then are mixed with each other, then malic acid is added therein before agitating at room temperature, and then ammonia liquor is dropped therein to adjust the pH value, so as to obtain nanometre Ce-Mg composite oxide after evaporating solvent, drying and calcining. The self-propagating combustion method has reaction substrate of cerium nitrate hexahydrate and magnesium nitrate, and has a complexing agent of malic acid, wherein the malic acid is dissolved in water, then cerous nitrate and magnesium nitrate are added therein synchronously before agitating at room temperature, and then ammonia liquor is dropped therein to adjust the pH value, so as to obtain nanometre Ce-Mg composite oxide after evaporating solvent, drying and calcining. The two methods can all obtain Ce-Mg composite oxide powder having a small particle diameter, a uniform dispersion and a large specific surface.

Description

technical field [0001] The invention relates to two methods for preparing nano-cerium-magnesium composite oxides, and belongs to the technical field of preparation of ultrafine cerium-magnesium composite oxide powders. Background technique [0002] Nano-cerium-magnesium composite oxide is a new multifunctional nanomaterial with perovskite structure, which has a wide range of applications. Nano-cerium-magnesium composite oxides are more widely used in automobile exhaust treatment and other catalytic fields because of their better high temperature resistance than single rare earth oxide ceria. It can also be used as a catalyst carrier or cocatalyst in industrial catalytic processes. Since the nano-cerium-magnesium composite oxide has high permeability to visible light (400nm-700nm) and strong absorption to ultraviolet light (200nm-400nm), it can be used for anti-aging and anti-ultraviolet materials of rubber, and can also be It is mixed with fluoresce...

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Problems solved by technology

However, the precipitation method has many factors affecting the product, which makes it difficult to control the conditions, and requires high-temperature calcination, which requires high equipment and consumes a lot of energy; the solid-phase method reacts unevenly, resulting in different particle sizes and uneven dispersion of the obtained samples; The emulsion method is not very mature in the production process, and it cannot be applied to industrial production on a large scale. In addition, the raw material cost of this method is high, and organic solvents or organic raw materials are often used in the preparation process to pollute the environment, and the obtained precursor need high temperature treatment

The sol-gel method in the prior art usually uses metal alkoxides as raw materials, resulting in high cost, certain toxicity, and poor environmental protection effect; the self-propagating method usually uses citric acid as a raw material for the preparation of oxides, and is currently used for The preparation of nano-cerium-magnesium composite oxide has not been reported yet

Due to the existence of high production costs, complex production processes, harsh reaction conditions, high product prices and environmental pollution in the above-mentioned methods, their application in industrial production is limited.

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