Copper-silicon catalyst and preparation method thereof

Abstract

The invention provides a copper-silicon catalyst and a preparation method thereof. The copper-silicon catalyst comprises a carrier and an active component, wherein the active component is a silicon-copper multi-component alloy, the silicon-copper multi-component alloy comprises a Cu element, a Si element and an M element, and the M element is at least one of Cr, Ni, Mo, Ti, Zr, Ce, La and Sc. The active components of the copper-silicon catalyst are fine in crystal grain, so that the interface defect active center and the silicon-copper phase interface are effectively increased. The catalyst is applied to a cold hydrogenation reaction process, and silicon tetrachloride directly reacts with an active component silicon-copper phase in the catalyst, so that the catalytic reaction time is greatly shortened, and the catalytic reaction rate and the conversion rate can be effectively improved.

Description

Technical field [0001] The present invention relates to the field of polysilicon production techniques, and more particularly to a copper silicon-based catalyst and a preparation method thereof. Background technique [0002] A large amount of tetrachloride and hydrogen chloride by-products are produced during the production of polysilicon, and the silicon tetrachloride has high pollution and cannot be discharged directly. The current industry to achieve the recovery of silicon tetrachloride recovery is to utilize chloride (ie The cold hydrogenation is reacted, and the catalysis of the silicon tetrachloride is converted to trichloride, and after purification is purified, the recovery of tetrachloride, wherein the catalyst is the most critical factor determining the conversion of hydrogenation. [0003] At present, the tetrachloride (STC) cold hydrogenation process used in domestic polysilicon manufacturers is carried out in a fluidized bed reactor. In many catalysts, copper chlori...

AI Technical Summary

Problems solved by technology

[0004] However, the cuprous chloride catalyst has the following problems in use: (1) the time for diffusion between cuprous chloride and silicon powder is short, and the reaction generates a small amount of silicon-copper phase; (2) the hydrochlorination reaction process In the silicon powder, the crystal grains are coarse, the grain boundaries and other defect centers are less, and during the hydrochlorination reaction, the content of the silicon-copper phase formed and defects such as the copper-silicon interface are less, and the catalytic active centers are less; (3 ) The migration of electrons, the adsorption and dissociation efficiency of silicon tetrachloride in the hydrochlorination reaction process are low; (4) limited by the fluidized bed filtration system, the small cuprous chloride cannot be fully utilized and flows into the back-end system, Abandoned as waste treatment, resulting in waste; (5) The efficiency of cold hydrogenation needs to be further improved, and the catalyst unit consumption and cost need to be reduced

However, this method only forms a silicon-copper phase interface on the surface of silicon powder, and the interface defect density is small

Chinese patent 201410267261.X discloses a method for preparing a cold hydrogenation catalyst by melting, shaking, pouring, and cooling. Easy to lose, causing unnecessary waste