A Direct Synthesis of making organohalosilanes with greater selectivity to
the dialkyldihalosilane is disclosed herein. By using nanosized copper
catalyst precursors, and preferably nanosized promoters as well, D/T
values of greater than 10, and preferably greater than 15, are obtainable
with silicon conversions in excess of 80 wt. %. Shorter induction times
are realized using the nanosized copper catalysts in the Direct
Synthesis. The nanosized copper catalyst precursors most preferably have
an average particle size of less than 100 nanometers.