Preparation of alkylhalosilanes

摘要

An alkylhalosilane is prepared by charging a reactor with a contact mass comprising metallic silicon powder and a copper catalyst and feeding a reactant gas containing an alkyl halide into the reactor whereby the silane is formed by direct synthesis. A phosphorus compound is added to the contact mass in an amount of 3,000-10,000 ppm calculated as phosphorus. The invention produces a more amount of dialkyldihalosilane in a desirable STY while minimizing the amount of unnecessary disilanes.