Surface chemistry of TiCl4 on clean and hydrogen modified W(1 1 0): identification of surface intermediates

The adsorption and decomposition of titanium tetrachloride (TiCl4) on W(1 1 0) were studied with high-resolution core level photoelectron spectroscopy. At least two stable intermediates are formed along the pathway to TiCl4 decomposition: TiCl4(a), which is stable up to 300 K, and TiCl3(a), which is stable up to 500 K. Successive adsorption at 80 K shows that the TiCl4(a) species forms in the presence of dissociated TiCl4 or hydrogen. This indicates that dissociative sites must be blocked before TiCl4 can adsorb intact.