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

Abstract

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.