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

Abstract

The invention provides a catalyst for hydrogenating silicon tetrachloride to prepare trichlorosilane and a preparation method thereof. A silicon source acidic solution containing silicon oxide is acidified, soluble salts of active components and additives are added, and then pseudo-thin The waste fine powder produced during the catalytic hydrogenation of diaspore and fluidized bed silicon tetrachloride is then added with a curing agent to form a slurry; the slurry is solidified and formed by spray drying, and then washed, dried, and roasted to form a catalyst. The trichlorosilane catalyst prepared by the present invention has round particle size, concentrated particle size distribution, large specific surface area and high active metal dispersion; the method of the present invention makes the fluidized bed silicon tetrachloride catalytic hydrogenation process The waste fine powder produced by the friction between silicon powder and the reactor, the friction between silicon powder and the silicon powder, and the friction between the silicon powder and the catalyst are made into the catalyst carrier, so that the waste fine powder can be reused, while increasing the added value of the waste fine powder, Reduce secondary pollution.

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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