Preparation of organohalosilanes

A process for preparing organohalosilanes comprising combining hydrogen, a halosilane having the formula HaSiX4-a (I) and an organohalide having the formula RX (II), wherein R is C1-C10 alkyl or C4-C10 cycloalkyl, each X is independently halo, and the subscript a is 0, 1, or 2, in the presence of a sufficient amount of a catalyst effective in enabling the replacement of one or more of the halo groups of the halosilane with the R group from the organohalide, at a temperature from 200 to 800° C., to form an organohalosilane and a hydrogen halide, wherein the volumetric ratio of hydrogen to halosilane is from 1:3 to 1:0.001 and the volumetric ratio of hydrogen to organohalide is from 1:1 to 1:0.001, and wherein the catalyst is optionally treated with the hydrogen or the halosilane prior to the combining.