Research On The Preparation Of Silane By The Disproportionation Of Triethoxysilane

Silane as a silicon component for the gas source can be used in the manufacture of high purity polycrystalline silicon, because the high purity and achieve precise control has become the source of many other silicon can not replace the important special gases, Now The main method is by hydrochloric acid and magnesium silicide reaction to produce silane. In this paper, triethoxysilane as a raw material prepared silane by the disproportionation reaction. This method is a system for a new silane process. The advantages of this process is high purity silane, non-corrosive, and non-polluting.Through research the solution, temperature, catalyst and drug pretreatment factors, We identified three triethoxysilane disproportionation producing silane process parameters: as 30g triethoxysilane for standard, the amount of THF is best 20 ml, the reaction temperature is 70～73°C, the catalyst best dosageis 1.5g, the amount of catalyst 1.0g, the reaction time is 3 hours. By GC-MS, GC qualitative analysis to ascertain the disproportionation reaction by-products is (H5C2O)3SiOSi(OC2H5)3. By the gas chromatography and quantitative analysis, we confirmed the product yield.We Studied the triethoxysilane disproportionation mechanism of the silicon structure and silane coupling mechanism of the chemical bonding theory, identified triethoxysilane disproportionation reaction mechanism, fluoride ion coordination weakened Si-H bond. leading to the oxygen atoms of silicon atoms caused by the pro-nuclear offensive.We also explored the silane oxidation mechanism that a silane oxygen in the combustion is the chain reaction. Silane hydrolysis product by X-ray powder diffraction, scanning electron microscopy tests confirmed silane surface combustion produces nano-amorphous silicon and silicon dioxide.