Modified Catalysts For The Hydrogenation Of Silicon Chloride To Prepare Of Trichlorosilane

With the deterioration of the energy crisis and environmental pollution,solar energy as a clean and renewable resources has attracted much attention,and the silicon material as an important raw material of solar photovoltaic industry,especially the high purity polysilicon,the preparation method is in continuous exploration.At present,the main method of industrial production of high purity polysilicon is trichlorosilane reduction,but with every production of 1 tons of polysilicon,the silicon tetrachloride by-product will have more than 10 tons.By the hydrogenation of silicon tetrachloride,the silicon tetrachloride by-product convert to trichlorosilane raw material is a green chemical production route for energy saving and emission reduction.This paper is based on the nickel based catalyst,through the silicon dioxide supported,and the introduction of barium chloride additive is prepared for the first time to make the catalyst BaCl₂-Ni/SiO₂ for the hydrogenation of silicon tetrachloride to trichlorosilane.Through the different content of BaCl₂ added to SiO₂ as the carrier,nickel as active centers of the catalyst precursor,to assess the value of BaCl₂ promoter effect on the performance of nickel based catalyst.Discover the structure of nickel silicide intermetallic compounds can be modulated by the introduction of BaCl₂ and the catalyst can improve reaction activity of silicon tetrachloride hydrogenation.The 1%BaCl₂-Ni/SiO₂ catalyst has the optimal catalytic activity,and after the reaction,the structure of Ni₃Si is formed on the surface which has the lowest silicon nickel than.In the condition of nickel loading is 5%,the flow rate of raw material gas is 5ml/min?catalyst bed volume is 560 ml?,reaction temperature is 800?,n?H2?:n?SiCl4?=6:1,the 1%BaCl₂-Ni/SiO₂ catalyst for the conversion of silicon chloride is 23.9%,and the Ni/SiO₂ catalyst is only 11.8%,this indicates BaCl₂ addition can significantly improve the catalytic activity of nickel silicide catalyst.