کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5425482 | 1395857 | 2006 | 15 صفحه PDF | دانلود رایگان |
This work presents results on the dissociation of H2S over Ni-Mo catalysts suggesting that the presence of surface Mo-atom(s) has a significant impact on both the energetics of the process and the reaction mechanism. The presence of one Mo atom provides an additional energetic advantage of 10.2Â kcal/mol overall. While increasing the energetic advantage of the process, the presence of Mo atom also increases the activation barriers by at most 3Â kcal/mol. The large exothermic nature of this process combined with the comparatively small activation barriers suggests that the H2S dissociation process is a facile process on all of the surfaces studied here. Additionally, analysis was provided to explain the difference in catalytic behavior between a bi-metallic alloy and a bi-metallic sulfide. It was determined that the bi-metallic alloy binds sulfur strongly (>100Â kcal/mol) which can be compared with the results of Sun and co-workers [M. Sun, A.E. Nelson, J. Adjaye, Catal. Today 105 (2005) 36] who predict that S adsorption on the metal sulfide phase is not energetically favorable. It is suggested that the sulfide surface does not bind S in an energetically favorable manner because the sulfide surface structure does not possess a binding site that can emulate the hollow site on a metal surface.
Journal: Surface Science - Volume 600, Issue 16, 15 August 2006, Pages 3202-3216