Abstract: An improvement in process for making cupreous catalyst composition, wherein a copper oxide-preponderant grind charge derived from the oxidation of elemental copper and/or an alloy thereof is subject to high energy milling with concomitant crystal lattice distortion until the average particle of the resulting grind is no larger than about 20 microns, comprises establishing a tin concentration between about 400 and about 3000 ppm in said composition prior to or after said high energy milling. The resulting catalyst is useful for producing organohalosilane from alkyl chloride and silicon.

Abstract: A grind charge of cupreous particulates containing a major proportion of cuprous and cupric oxides and a minor proportion of elemental copper, said charge having average particle size above 15 microns, is subjected to high energy comminution with concomitant crystal lattice distortion until the average particle size of said particulates is no larger than 15 microns. The resulting catalyst, of fairly high specific surface area, can be used for alkyl or aryl halosilane production.

Abstract: Improved catalyst is made by including in a grind charge of cupreous particulates a small proportion of a hydroxide of Period IV metal having Atomic Number between 24 and 30, e.g. iron III oxide monohydrate. Said grind charge contains a major proportion of cuprous and cupric oxides, a minor proportion of elemental copper, and up to about 10% of promoter material. Such charge is subjected to high energy comminution with concomitant crystal lattice distortion. The catalyst is useful for the production of alkyl and aryl halosilanes.