Multi-shell-layer hollow-core-shell cubic structure type M1.8M'1.2O4@CeO2 composite material and preparation method thereof

Abstract

The invention discloses a multi-shell-layer hollow-core-shell cubic structure type M1.8M'1.2O4@CeO2 composite material and a preparation method thereof. The preparation method comprises the steps of firstly synthesizing a uniformly dispersed Prussian blue-similar metal organic framework material MM'-PBAs cubic structure, roasting MM'-PBAs at a high temperature under a specific condition so as to obtain a multi-shell-layer transition metal multiple oxide M1.8M'1.2O4 hollow cubic box based on an unbalanced thermal treatment method, and assembling a thickness-controllable CeO2 shell layer formedby nanometer crystals to the surface of M1.8M'1.2O4, so as to obtain the M1.8M'1.2O4@CeO2 core-shell cubic box. The process is simple, mild in condition and high in yield, a multi-shell-layer hollow structure material is directly obtained without use of a template or additional cavitation; the prepared material has a hollow structure and is large in specific surface area, meanwhile, the internal space can be effectively utilized by virtue of the multi-layer hollow structure, the contact area between substrate molecules and the material is increased, and more active sites are exposed, so that the catalytic oxidation performance is excellent.

Description

technical field [0001] The invention belongs to the field of inorganic nanomaterials and heterogeneous catalysis, and relates to a rare earth-transition metal composite oxide, in particular to a multi-shell hollow core-shell cubic structure M 1.8 M' 1.2 o 4 @CeO 2 Composite materials and methods for their preparation. Background technique [0002] The application of metal oxide materials in the fields of catalysis, sensing, and energy storage is directly related to the structure of the material. As a typical structure, the nano- or micro-scale multi-shell hollow structure has the characteristics of low density, large specific surface area, hollow structure, and multi-shell composed of nanoparticles, so it is widely used in fields related to surface properties. . [0003] At present, there are few reports on the preparation of metal oxides with multi-shell non-spherical hollow structures, especially rare earth-transition metal composite oxides. According to the existing...

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Problems solved by technology

However, when surfactant-based micelles, reverse micelles, and microemulsion droplets are used as soft templates, in order to minimize the surface energy, they usually tend to form spherical structures, so they are not suitable for non-spherical nanostructures (especially polyhedral structure) formation

Even the preparation of non-spherical nanostructures using the hard template method still has certain difficulties, such as how to coat a uniform shell on the surface of the template with a large curvature change

Because non-spherical templates may have different crystal faces, and different crystal faces have different reactivity and crystal growth rate, making uniform coating more difficult

[0004] The reported CeO 2 Most of the core-shell nanoparticles that are the shell are based on noble metals such as Ag, Au, Pt, Pd and other nanoparticles as the core, or the obtained composite metal oxide hollow structure product has poor dispersion and low porosity, which is not conducive to substrate reaction molecules. Mass transfer and diffusion, and it is difficult to achieve fine regulation of morphology, structure and chemical composition, which greatly limits its practical application in the field of catalysis

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