Adsorption and Reactions of Cyclic Sulfides on Mo(110)

摘要

Molecular orbital calculations of the chemisorption and reactivity of ethylene sulfide and trimethylene sulfide on molybdenum (110) are presented, and compared to similar binding in model discrete Mo complexes. Our calculations suggest preferred bonding of the cyclic sulfides on 2- or 3-fold sites of the surface, by the expected S-lone pair donor mechanism. The concerted elimination of ethylene or cyclopropane is much easier on the surface than it is in model organometallic molecules. The activation barrier for ethylene sulfide decomposition calculated is substantially smaller than for trimethyylene sulfide. Various nonconcerted mechanisms and the role of coadsorbed sulfur and hydrogen were also probed. (aw)