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 investigations, that transition metals in an H2SiCl4 atmosphere in the temperature range 600-1200 K will react to form metal silicides. With rising temperature, stoichiometry will change in the direction of silicides 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 silicides, systematization of silicide formation is possible.