Preparation method and application of nanosheet vanadium phosphorus oxygen catalyst for strengthening microscopic mixing and reaction

Abstract

The invention discloses a preparation method of a nanosheet vanadium phosphorus oxide catalyst for strengthening microscopic mixing and reaction. The preparation method comprises the following steps:s1, dissolving V2O5 in a first stirring kettle for reduction reaction; s2, mixing supergravity reinforced phosphoric acid with a tetravalent vanadium turbid liquid in the step S1 and reacting; s3, after aging in a second stirring kettle is finished, performing suction filtration on a turbid liquid, repeatedly washing an obtained filter pulp with ethanol for 2-4 times, and then drying and activating a filter cake to obtain the nanosheet vanadium phosphorus- oxygen catalyst; collecting the obtained filtrate; s4, separating the filtrate by using a supergravity rectification device; and proportioning a tower bottom liquid material subjected to vacuum rectification and a fresh solvent, and directly conveying to a first stirring kettle for recycling. According to the invention, the micron-scaleflower-like accumulation morphology of the traditional VPO catalyst is stripped into a nano-sheet structure by virtue of supergravity.

Description

technical field [0001] The invention relates to the technical field of catalyst preparation. More specifically, it relates to a preparation method and application of a nano-sheet vanadium-phosphorus-oxygen catalyst that strengthens microscopic mixing and reaction. Background technique [0002] Maleic anhydride (MA) is an important organic chemical raw material and fine chemical product, which has a wide range of applications and a huge market demand. At present, the industrial production of maleic anhydride is mainly based on the oxidation of benzene and n-butane. Compared with the traditional benzene method, the n-butane oxidation method has the following irreplaceable advantages: the raw material energy consumption of the n-butane oxidation method is small, and the theoretical yield of maleic anhydride is high. 1.1 tons of butane feed gas can produce about 1 ton of MA, and the theoretical output is as high as 1:1.69 (raw material / maleic anhydride), while the benzene oxid...

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Problems solved by technology

However, the maleic anhydride production technology in my country is still dominated by the benzene oxidation method with high pollution, high cost, and low product yield, and the production capacity occupancy rate of the n-butane oxidation method is less than 40% (according to statistics, it was 37.2% in 2018)

The comparison of the catalysts prepared by the two methods shows that the catalyst prepared by the former has good crystallinity and can generate α-(VO) with an approximate ideal structure. 2 P 2 o 7 phase, the structure is stable, and there are few deep oxides formed, but the specific surface area is less than 10m 2 / g, there are defects of low reaction rate and high reaction temperature; the catalyst prepared by the latter, when the precursor matrix is ​​generated, the disorder of the solvent molecules increases, and the heterogeneous β-(VO)2P2O7 phase is generated, but the specific surface area is high. 30-60m 2 between / g

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