Mechanism of the silicide-catalysed hydrodehalogenation of silicon tetrachloride to trichlorosilane

A mechanism of transition metal silicide-catalysed hydrodehalogenation of silicon tetrachloride to trichlorosilane is proposed. The overall reaction includes electron transfer steps from the metal silicide catalyst to adsorbed silicon tetrachloride molecules. A silylene species (SiCl2) which is formed from SiCl4 and the catalyst surface, is proposed. A hydrogen molecule injects electrons into the solid, whereby hydrogen chloride is generated on the surface. Trichlorosilane results from the oxidative addition of HCl to chemisorbed SiCl2.