Abstract
Ti films grow on Ru(0001) in a layer-by-layer mode, a (√91 × √91)R5.2 ° LEED pattern appearing at loadings close to monolayer completion. Such films are extremely active towards H 2 and CO chemisorption, although in both cases no aggregation of the Ti deposit occurs as a result. The uptake of β-CO (characteristic of clean Ru) is strongly suppressed by Ti dosing: this effect is markedly nonlinear and the results suggest that islands of Ti exert a significant long-range influence on the chemisorption of CO by Ru. Isotope data show that the presence of Ti leads to the formation of dissociatively adsorbed CO, while hydrogen chemisorption results in a surface hydride species of limiting stoichiometry TiH 3. This latter species decomposes at ~600 K with concomitant formation of an RuTi surface alloy; the TiH 3 surface hydride is itself very active in the dissociative chemisorption of CO. The relevance of these findings to aspects of the SMSI phenomenon and to K-promoted Ru is discussed.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
