H. I. and, J. White
Jun 10, 2000
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0
Influential Citations
61
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Journal
Journal of Physical Chemistry B
Abstract
The thermal reactions of phenol on Pt(111), including reaction intermediates, have been studied between 125 and 1100 K by using phenol-h6, phenol-2,4,6-d3, phenol-2,3,4,5,6-d5, and phenol-d6 with temperature-programmed desorption (TPD), high-resolution electron energy loss spectroscopy (HREELS), and X-ray photoelectron spectroscopy (XPS). Phenol adsorbs molecularly at 125 K, with the ring plane parallel to the surface. During heating, the O−H bond breaks below 200 K. The O−H bond dissociation product, phenoxy, has a quinoidal structure with η5-π-adsorption geometry via the C2 through C6 atoms with the C1 atom tilted away from the ring plane. Bonds in the phenoxy species rearrange toward oxocyclohexadienyl upon heating. The reactivity of phenoxy depends on the initial phenol coverage. Below 0.5 monolayer (ML), phenoxy fully decomposes to CO(g), H2(g), and C(a). Above 0.7 ML coverages, it follows two different pathways: (1) 85 ± 7% forms CO(g), H2(g), C2(a), and C3H3(a) at 490 K, the latter dehydrogenating...