Method for preparing core-shell type VPO@SiO2 catalyst

The invention relates to a preparation method of a mesoporous silica-coated vanadium phosphorus oxide nanoparticle (VPO@SiO2) catalyst, is used in a process of preparing acrylic acid through formaldehyde acetic acid hydroxyl aldehyde condensation, and belongs to the technical field of organocatalysis. A method for preparing a core-shell type VPO@SiO2 catalyst comprises the steps that firstly, a vanadium phosphorus oxide nanoparticle is prepared, and then the surface of the vanadium phosphorus oxide nanoparticle is covered with a silicon dioxide layer to prepare the core-shell type VPO@SiO2 catalyst. The core-shell type VPO@SiO2 catalyst has the advantages that the protective effect of a shell layer is utilized to prevent the agglomeration and loss of active components in the reaction process, the stability of the catalyst is improved, and the service life of the catalyst is prolonged; and the formaldehyde acetic acid hydroxyl aldehyde condensation reaction to prepare the acrylic acid is stably catalyzed for a