Carbon−Carbon Bond Activation in Adsorbed Cyclopropane by Gas-Phase Atomic Hydrogen on the Ni(111) Surface

Abstract

Gas-phase atomic hydrogen induces C−C bond activation in adsorbed cyclopropane on the Ni(111) surface, while coadsorbed hydrogen does not. Propane is the only desorbing product observed during subsequent temperature-programmed desorption experiments. Three propane formation pathways are observed. Gas-phase atomic hydrogen reacts with adsorbed cyclopropane to form intermediates at 105 K, which are hydrogenated by coadsorbed hydrogen to form propane at 116 and 210 K. The 116 K pathway is similar to previous results obtained on the Ni(100) surface where propyl was determined to be the primary intermediate. The 210 K pathway has no analogue on the Ni(100) surface and is thought to involve a more stable form of propyl on the Ni(111) surface. The reaction of subsurface hydrogen with adsorbed cyclopropane leads to propane formation at 170 K on the Ni(111) surface. The absence of methane and ethane formation indicates that no multiple C−C bond activation processes occur. In contrast, cyclopropane desorption occur...