Catalyst, preparation method thereof and application thereof

Abstract

A catalyst and a preparation thereof are disclosed. The preparation method comprises the following steps: allowing a soluble nickel salt to contact with a silicon source which can provide silica and a precipitating agent which precipitates nickel irons in a solvent; and filtering products obtained after contact, drying the resulting solid, roasting, carrying out temperature programming reduction, and passivating. An application of the catalyst of the invention in the preparation of trichlorosilane from silicon tetrachloride through hydrogenation is also disclosed. According to the catalyst prepared through the preparation method of the invention, an SiO2 carrier in an atmosphere of a reaction that trichlorosilane is prepared from silicon tetrachloride through hydrogenation is stable, and the skeleton of the catalyst, which does not like that of traditional hydrogenation catalysts easy to destroy, is difficult to destroy, so the service life of the catalyst is long; and the catalyst of the invention has a higher activity than nickel salt and copper salt catalysts used in the prior art.

Description

technical field [0001] The invention relates to a catalyst preparation method, a catalyst prepared by the method, and an application thereof in preparing trichlorosilane by hydrogenation of silicon tetrachloride. Background technique [0002] In recent years, with the depletion of traditional energy sources worldwide and the continuous increase in oil prices, the world is actively developing and utilizing renewable energy. As a renewable clean energy, solar energy has developed rapidly because of its cleanliness, safety and abundant resources. Therefore, the demand for high-purity polycrystalline silicon as a raw material for solar cells is increasing. [0003] In the polysilicon production process, the production of 1 ton of polysilicon will produce more than 10 tons of silicon tetrachloride and about 1-5 tons of hydrogen chloride. Since there is no large-scale, efficient and safe digestion and treatment of SiCl produced in the process of producing polysilicon 4 However,...

AI Technical Summary

Problems solved by technology

[0009] It can be seen from the background technology that the supported nickel-based catalysts of the prior art are generally used to carry out the hydrogenation of silicon tetrachloride at present, and there are few researches on the special catalysts for the hydrogenation of silicon tetrachloride, while the commonly used supported nickel-based catalysts of the prior art In the hydrogenation process of silicon tetrachloride, there are still problems such as poor catalyst stability, easy loss of active components and easy agglomeration. There is a large difference, which leads to the aforementioned problems in the hydrogenation catalyst prepared by the preparation method according to the prior art (generally adopting soluble salts to be loaded on the carrier, drying and roasting) to be used in the hydrogenation process of silicon tetrachloride. Based on this , the inventor of the present invention tries to imagine whether a new method for preparing a hydrogenation catalyst can be developed so that the prepared catalyst can be more suitable for the hydrogenation reaction of silicon tetrachloride, so that it can be used as a special-purpose catalyst for the hydrogenation reaction of silicon tetrachloride in the future. catalyst

The inventors of the present invention have found through experiments that in the traditional process of preparing a hydrogenation catalyst (generally, a loading process in which a soluble salt is used to load a carrier), a precipitant is added for loading and then dried and roasted, and the solid obtained after roasting is further Reduction and passivation can make the prepared catalyst used in the hydrogenation of silicon tetrachloride no longer have the aforementioned problem of poor stability leading to reduced activity. Based on this finding, the present invention has been completed

Images