Preparation method of magnesium and aluminum doped mesoporous hollow sphere ceria-based oxygen storage material

Abstract

The invention discloses a preparation method of a magnesium and aluminum doped mesoporous hollow sphere ceria-based oxygen storage material and belongs to the technical field of oxygen storage material preparation. The method includes: weighing sodium silicate and water, dropwise adding hydrochloric acid solution, performing ultrasonic dispersion to obtain dispersion liquid, adding magnesium nitrate solution, aluminium nitrate solution, acetone and acetylacetone cerium, enabling the matters to be loaded to the surface of orthosilicic acid sediment under the action of ammonia water titration, performing calcination under nitrogen atmosphere after dehydration, washing with ethyl alcohol, sodium hydroxide solution and deionized water, and filtering to obtain filter residue prior to activation to prepare the magnesium and aluminum doped mesoporous hollow sphere ceria-based oxygen storage material. The preparation method has the advantages that the preparation steps are simple, specific surface area is increased effectively, and oxygen storage capacity is increased by 22-26%; the obtained produce is of a spatial stereostructure, and under the condition of over 1123K, sintering is avoided, and the oxygen storage capacity and the specific surface area are unchanged.

Description

technical field [0001] The invention relates to a preparation method of a cerium-based oxygen storage material doped with magnesium and aluminum mesoporous hollow microspheres, and belongs to the technical field of preparation of oxygen storage materials. Background technique [0002] Oxygen storage materials, powders, have different colors depending on the elements contained, mainly yellow, brown, etc.; binary or multi-component composite oxides composed of rare earth elements, alkaline earth metal elements or transition metal elements mainly composed of cerium oxide . The composition of the first-generation cerium-based oxygen storage materials is pure CeO 2 , its main feature is that the oxygen storage performance depends on the specific surface area, the thermal stability is poor, and the specific surface area decreases rapidly after aging above 850 ° C, thus losing the oxygen storage performance; the composition of the second-generation cerium-based oxygen storage mate...

AI Technical Summary

Problems solved by technology

The composition of the first generation cerium-based oxygen storage materials is pure CeO 2 , its main feature is that the oxygen storage performance depends on the specific surface area, the thermal stability is poor, and the specific surface area decreases rapidly after aging above 850 ° C, thus losing the oxygen storage performance; the composition of the second-generation cerium-based oxygen storage material is CeO 2 -ZrO 2 , which is characterized by the fact that both the surface and the bulk phase of the oxygen storage material can store oxygen, so the oxygen storage performance not only depends on the specific surface area of ​​the material, but the thermal stability of the texture is poor at high temperature, and the specific surface area decreases rapidly, thus affecting the oxygen storage / release performance The third generation of cerium-based oxygen storage materials is still in the development stage, and the research focus is mainly on low-valent ions such as Y 3+ , La 3+ 、Al 3+ Equally doped CeO 2 -ZrO 2 Solid solution, the purpose is to increase oxygen ion defects in the bulk phase to improve the structure, texture and oxygen storage performance of CeO2-ZrO2 solid solution

But above 1123K, CeO 2 Easy to sinter and lose the porous structure, thereby reducing the oxygen storage capacity and specific surface area