Catalyst for preparing trichlorosilane by hydrogenation of silicon tetrachloride and preparation method thereof

Abstract

The invention provides a trichlorosilane catalyst prepared from silicon tetrachloride through hydrogenation and a preparing method of the trichlorosilane catalyst. The method includes the steps of conducting acidification treatment on a silicon source acidic solution containing silicon oxide, adding active components and soluble salt of aids, adding pseudo-boehmite and abandoned micropowder generated in the silicon tetrachloride catalytic hydrogenation process of a fluidized bed, adding a curing agent to prepare slurry, conducting solidification forming on the slurry by means of a spray dryingmode, and conducting washing, drying and calcinating to prepare the catalyst. The trichlorosilane catalyst prepared through the method is uniform in granularity and concentrated in grain size distribution, and has a large specific surface area and high reactive metal dispersity; by means of the method, the catalyst carrier is prepared from the abandoned micropowder generated by making the siliconpowder in the silicon tetrachloride catalytic hydrogenation process of the fluidized bed rub a reactor, making the silicon powder rub the silicon powder and making the silicon powder rub the catalyst, the abandoned micropowder is reused, and secondary pollution is reduced when the additional value of the abandoned micropowder is increased.

Description

Technical field [0001] The invention relates to a catalyst for preparing trichlorosilane by hydrogenating silicon tetrachloride and a preparation method thereof. Background technique [0002] With the gradual depletion of fossil energy and the increasing environmental pollution problems, the search for a pollution-free renewable energy has become a top priority. As the most abundant renewable energy, solar energy has the advantages of cleanliness, safety, versatility, resource adequacy and potential economy compared with other energy sources. Making full use of solar energy has important economic and strategic significance for achieving sustainable development in a low-carbon model. [0003] In recent years, the output of polycrystalline silicon in my country has increased sharply. The main production processes of polycrystalline silicon include modified Siemens method, silane method and fluidized bed method. Among them, the modified Siemens method is the mainstream technology for...

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Problems solved by technology

[0004] Silicon tetrachloride is a poisonous and harmful gas. If it is discharged arbitrarily without treatment, silicon tetrachloride will combine with water vapor in the atmosphere to produce hydrogen chloride gas, which will cause serious pollution to the environment. In addition, it will also cause extreme resource consumption. Big waste, increasing the production cost of the enterprise

However, the catalyst prepared by this method is powdery, and it is easy to "run away" when used in a fluidized bed, resulting in catalyst loss and reduced activity. At the same time, the specific surface area of ​​the catalyst is not disclosed in the above-mentioned patent, indicating that silicon is simply used as a carrier for co-precipitation The specific surface area of ​​the prepared catalyst should be very small. A catalyst with a small specific surface area cannot provide more reaction sites for the reactants, which will affect the activity of the catalyst.

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