Competing pathways for methoxy decomposition on oxygen-covered Mo(110)
- 8 October 1998
- journal article
- research article
- Published by AIP Publishing in The Journal of Chemical Physics
- Vol. 109 (14) , 6067-6074
- https://doi.org/10.1063/1.477232
Abstract
The reactions of methanol ( CH 3 OH ) are investigated on a range of oxygen overlayers on Mo(110), with θ O from ∼0.5 to >1 ML, using a combination of vibrational spectroscopies and temperature-programmed reaction.Infrared spectroscopy identifies a common, tilted methoxy intermediate at high temperature on all overlayers studied; electron energy loss spectroscopy shows that this intermediate decomposes to deposit oxygen exclusively in high-coordination sites. While C–O bond scission to evolve gas-phase methyl radicals is the only reaction observed for methoxy on highly oxidized Mo(110), on the surface oxygen overlayers competition between dehydrogenation and methyl evolution is highly sensitive to oxygen coverage. The enhanced selectivity for hydrocarbon formation from methanol reaction on oxygen-modified Mo(110) relative to the clean surface is attributed to inhibition of dehydrogenation pathways rather than to marked changes in the C–O bond potential of methoxy.Keywords
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