Patent ID: 7238638

Claim:
A process for the direct synthesis of alkylhalosilanes while diminishing the undesirable formation of coke, comprising reacting an alkyl halide with silicon in the presence of a catalytically effective amount of (α) a copper metal or a copper-based compound catalyst and (β) a catalyst promoter intermixture therefor which comprises an effective minor amount of an additive β1 selected from the group consisting of tin, a tin-based compound and mixture thereof, optionally, an effective minor amount of an additive β2 selected from the group consisting of zinc metal, a zinc-based compound and mixture thereof, an effective minor amount of an additive β3 selected from the group consisting of cesium, potassium and rubidium, and compound and mixture thereof, and, an effective minor amount of an additive β4 selected from the group consisting of the element phosphorus, a phosphorus-based compound and mixture thereof; wherein the additives β3 and β4 are present in such amounts that the ratio: number ⁢ ⁢ of ⁢ ⁢ gram ⁢ ⁢ atoms ⁢ ⁢ of ⁢ ⁢ alkali ⁢ ⁢ metal number ⁢ ⁢ of ⁢ ⁢ gram ⁢ ⁢ atoms ⁢ ⁢ of ⁢ ⁢ elemental ⁢ ⁢ phosphorus ranges from 1 to 20.