Michael B. Griffin, S. Pang, J. Medlin
Feb 1, 2012
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Influential Citations
14
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Journal
Journal of Physical Chemistry C
Abstract
Temperature-programmed desorption (TPD), high-resolution electron energy loss spectroscopy (HREELS), and density functional theory (DFT) were used to investigate the thermal surface chemistry of 2-iodoethanol (ICH2CH2OH) on Pd(111). 2-Iodoethanol undergoes C–I scission upon adsorption at low temperatures, resulting in 2-hydroxyethyl (−CH2CH2OH) formation. At low coverage, this intermediate decomposes to form carbon monoxide and hydrogen during TPD. At higher coverage, hydroxyethyl reacts to produce ethanol, ethylene, water, 2-iodoethanol, and acetaldehyde, with nearly complete suppression of the decarbonylation pathway. DFT and HREELS results indicate that the coverage dependence of the reaction pathways is correlated with a change in the adsorption geometry of hydroxyethyl. At low coverage the C–O bond lies parallel to the surface, while at higher coverage it is shifted into a perpendicular position. Adsorbed iodine is observed to play a significant role in blocking sites and favoring the upright adsorpt...