Composite catalyst for preparing trichlorosilane through catalytic hydrogenation of silicon tetrachloride

Abstract

The invention discloses composite catalyst for preparing trichlorosilane through catalytic hydrogenation of silicon tetrachloride. The active constituents of the catalyst comprise at least one second main group metallic element and at least one transitional metal element, or a compound of the second main group metallic element and that of the transitional metal element, and can be loaded on a carrier for use. The catalyst can be used for catalytic hydrogenation dehalogenation reaction of silicon tetrachloride in the atmosphere of 700 to 1000 DEG C and 1 to 30 bar hydrogen, has higher catalytic activity and favorable selectivity, and is low in cost, simple to prepare and stable in performance.

Description

technical field [0001] The invention relates to a catalytic reaction technology for heterogeneous gas-solid dehalogenation hydrogenation reaction in the field of chemical industry, in particular to a composite catalytic technology for catalytically hydrogenating silicon tetrachloride to convert silicon tetrachloride into trichlorosilane and hydrogen chloride. Background technique [0002] At present, the polysilicon industry at home and abroad is developing rapidly, and the process of producing high-purity polysilicon with trichlorosilane accounts for a large share of the production capacity that has been put into production. The by-product silicon tetrachloride produced by this series of processes is severely overcapacitated, and 14-20kg of silicon tetrachloride is produced for every 1kg of polysilicon produced, and has low utilization value, high waste disposal cost, high toxicity and high pollution. However, the technology of directly producing electronic-grade or photovo...

AI Technical Summary

Problems solved by technology

However, the metals or chlorides of the main group II also have a catalytic effect on side reactions, and the selectivity is relatively low, and by-products such as dichlorodihydrosilane are generated, resulting in waste of raw materials and energy.

However, silicon carbide nanotube arrays infiltrated with precious metals and special materials such as palladium, platinum, tungsten, and silicon, although this type of catalyst has a high selectivity to the product trichlorosilane, is expensive, has a short life, and is prone to sintering loss. The atomic dust produced by consumption at high temperature will also pollute the product and the environment