Conversion of a Direct Process high-boiling residue to monosilanes by a two-step catalysis approach

The effects of different kinds of catalysts and supports on the conversion of a Direct Process high-boiling residue to monosilanes were evaluated. A new method, a two-step catalysis approach, was used for catalytic decomposition and redistribution reactions. The effects of reaction temperature, volume ratio of starting materials, feeding rate and reaction pressure on the conversion were investigated. While employing activated carbon as the decomposition catalyst and gamma-Al2O3 for redistribution, which constituted the two-step catalysis approach, improved yield of methylchlorosilanes and dimethyldichlorosilane, and higher conversion of high-boiling components decomposition could be obtained. This two-step catalysis approach could be run under normal pressure or low pressure, which would solve the disadvantageous factors generated from the high-pressure process.