Method for controllably synthesizing vanadium phosphorus oxide catalyst by binary mixed solvent system

Abstract

The invention provides a method for regulating and controlling the structure of a vanadium phosphorus oxide material by using a binary mixed solvent consisting of ionic liquid / eutectic mixture-water or ionic liquid / eutectic mixture-organic solvent. The binary mixed solvent is used as a supramolecular catalyst; meanwhile, the reaction components are aggregated by a guiding agent, water or an organic solvent is used as an accelerant to promote the smooth completion of the process, and the finally synthesized vanadium phosphorus oxide material not only belongs to a nano material, but also is relatively high in crystallization rate, and overcomes the defects of low crystallization rate, low yield, small crystal grains or difficulty in crystallization of an ionothermal method. Meanwhile, the purpose of modulating the diffraction intensity, morphology and specific surface area of a vanadium phosphorus oxide crystal phase and a crystal face is achieved by modulating the composition of a specific binary mixed solvent; compared with an ionothermal method, a hydrothermal method and an organic solvent method, a template agent which is high in price and possibly pollutes the environment does not need to be additionally added, energy consumption and cost are lower, operation is easy, and safety and environmental protection are achieved.

Description

technical field [0001] The invention relates to the technical field of materials, in particular to a vanadium-phosphorus-oxygen catalytic material for controllable synthesis of a binary mixed solvent system. Background technique [0002] Vanadium-phosphorus-oxygen (VPO) catalysts have excellent ability to activate carbon-hydrogen bonds (C-H), especially in the selective oxidation of butane to maleic anhydride (MA). Therefore, the industry has not yet found a better catalyst to replace it [1]. The catalytic performance of vanadium-phosphorus-oxygen materials is closely related to its size and shape, so the controllable preparation of vanadium-phosphorus-oxygen catalysts with certain structural characteristics has a good application prospect. [0003] At present, vanadium-phosphorus-oxygen catalysts are mostly prepared by traditional hydrothermal or solvothermal methods. Low surface area, harsh reaction conditions (high pressure), cumbersome operation steps (the reaction pro...

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Problems solved by technology

However, the template ionic liquid may enter the material skeleton, resulting in the formation of impurity phases or unknown phases. In addition, due to the high viscosity of ionic liquids, the rate of synthesis of materials is very slow.

[0004]In summary, the three synthesis methods have their own advantages and disadvantages. Generally speaking, the materials obtained by ionic thermal synthesis in an ionic state environment with unique structures tend to be smaller in size and have better morphology. Diverse, but the synthesis rate is slow, and the materials obtained by hydrothermal and organic thermal synthesis methods in the molecular state environment are often large in size and single in shape, but the synthesis rate is fast, and it is not easy to produce unknown phases.

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