A kind of preparation method and application of vanadium phosphorus oxygen catalyst

Abstract

The invention relates to a vanadium phosphorus oxide catalyst, a preparation method and applications thereof. The preparation method comprises: placing a vanadium source in a container, adding a mixing liquid comprising isobutanol and benzyl alcohol according to a volume ratio of 2-6:1, heating to a temperature of 100-180 DEG C, carrying out a reaction for 2-8 h, cooling to a temperature of 30-80DEG C, adding glucose, adding a phosphorus source to the container, heating to a temperature of 100-200 DEG C, continuously carrying out a reaction for 10-24 h, filtering the product, washing the product, and drying to obtain a vanadium phosphorus oxide precursor, wherein a molar ratio of the phosphorus in the phosphorus source to the vanadium in the vanadium source is 0.8-1.5:1, the concentrationof vanadium pentoxide in the mixture of isobutanol and benzyl alcohol is 0.02-0.12 g / mL, and a mass ratio of the vanadium source to the glucose is 3-15:1; and calcining the vanadium phosphorus oxideprecursor for 10-24 h at a temperature of 350-550 DEG C, and cooling to obtain the vanadium phosphorus oxide catalyst. According to the present invention, the vanadium phosphorus oxide catalyst prepared by the method has large specific surface area; the preparation method is simple, and is suitable for large-scale preparation; and with the application of the vanadium phosphorus oxide catalyst in the maleic anhydride preparation reaction by catalyzing the selective oxidation of n-butane, the problems of low reaction yield, poor selectivity and the like of the maleic anhydride preparation reaction through the selective oxidation of n-butane in the prior art are improved.

Description

technical field [0001] The invention belongs to the field of chemical catalysis, and in particular relates to a preparation method and application of a vanadium-phosphorus-oxygen catalyst. Background technique [0002] Vanadium-phosphorus-oxygen catalyst is a composite oxide catalyst with defective structure, which is composed of three elements V, P, and O. Therefore, it has good electron and oxygen transport functions, and has a wide range of applications in the field of catalysis and electrochemistry. At the same time, the catalyst is currently the only catalyst for the selective oxidation of low-carbon alkanes that has been industrialized. Its crystal structure is relatively complex, and its active phase is also different for different reactions, mainly (VO) 2 P 2 o 7 、VOPO 4 etc. Different preparation conditions often lead to different crystal structures, and their catalytic performance and microscopic morphology are also quite different. Factors affecting its struc...

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Problems solved by technology

Most of the early catalysts were prepared by the aqueous phase method. At present, the preparation of VPO catalysts for industrial applications at home and abroad is by the organic phase method, but the catalysts prepared by this method still have problems such as small specific surface area, poor selectivity and easy over-oxidation.

Moreover, the catalyst obtained by the existing method has a limited number of active sites, the structure is easy to collapse, and the conversion rate is low; due to the complexity of the catalyst structure, the transformation between its phase states is often difficult to control, resulting in unstable catalyst performance

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