HYDRODEHALOGENATION OF CHLOROSILANES IN THE PRESENCE OF METAL SILICIDES - EXPERIMENTAL STUDIES OF GAS AND SOLID-PHASE COMPOSITION RELATED TO THERMODYNAMIC CALCULATIONS

Thermodynamic calculations show, in accordance with experimental inves tigations, that transition metals in an H2SiCl4 atmosphere in the temp erature range 600-1200 K will react to form metal silicides. With risi ng temperature, stoichiometry will change in the direction of silicide s with a higher silicon content. The silicides formed in situ act both as a catalyst and a silicon source for the hydrogenation reaction of SiCl4 to form silanes. On the basis of the formation enthalpy of the s ilicides, systematization of silicide formation is possible.