Abstract
The reaction of silicon with methanol using a copper (I) chloride catalyst in biphenyl at 220 °C for 10h gave a mixture of trimethoxysilane and tetramethoxysilane in an 82% silicon conversion. Under these conditions, the selectivity for trimethoxysilane was around 80%. The optimum conditions for the reaction were as follows; 200-220 °C of the temperature, dropwise addition of methanol for 10 h, (0.7-1.4) x 10-2 molar amount of the catalyst, and 6 molar amounts of methanol to metallic silicon.
Time course of this reaction was examined for 10 h. The amount of trimethoxysilane for mation reached a maximum in 2 h and then decreased monotonously. The yield of trimethoxysilane decreased rapidly after 7 h. While the cumulative silicon conversion increased linearly to ca.80% in 10 h, the selectivity for trimethoxysilane showed above 90% for 7 h and then decreased to 78% at the final. The overall selectivity for trimethoxysilane for 10 h was 90%.
Trimethoxysilane was found to suffer alcoholysis easily with a large excess of methanol to afford tetramethoxysilane at room temperature.
