Donna A. Chen, C. Friend, H. Xu
Jan 12, 1998
Citations
0
Influential Citations
6
Citations
Journal
Surface Science
Abstract
Abstract The desulfurization of benzenethiol on Co-covered Mo(110) ( θ Co = 0.25–1.3 ML) produces benzene, H 2 and adsorbed carbon and sulfur. Benzene is formed via adsorbed phenyl thiolate, which is identified by X-ray photoelectron and electron energy loss spectroscopies. Benzene production is attributed to reaction on Co, since it is evolved at a temperature well below that required for sulfur-induced aggregation of Co. The reaction products and mechanisms are qualitatively similar on Co-covered Mo(110) and a range of other transition metal surfaces. The selectivity for benzene production on the 1.3 ML Co overlayer, ∼ 65%, is higher than on many surfaces. Furthermore, benzene evolution occurs at a very low temperature, 125 K, on the 1.3 ML Co film. Notably, we did not observe any new products or a dramatic change in reaction temperature or selectivity as a result of CoMo interactions or of structural changes in the Co layer. Comparison of the benzene evolution temperature for benzenethiol reaction with that of methane from methanethiol reaction on the close-packed Co overlays indicates that homolytic CS bond scissions do not control the hydrogenolysis rate, in contrast to reaction on Mo(110) but similar to Ni(111). This difference may be due to hydrogen-induced structural transformations of the Co layer or to hydrogen-assisted CS bond breaking.