Low temperature CO oxidation on Au(111) and the role of adsorbed water

This paper presents results of an investigation of low-temperature CO oxidation and the role of moisture on an atomic oxygen covered Au(111) surface by employing molecular beam scattering techniques under ultrahigh vacuum (UHV) conditions. The effect of atomic oxygen precoverage on CO oxidation was...

Full description

Saved in:
Bibliographic Details
Published in:Topics in catalysis 2007-06, Vol.44 (1-2), p.57-63
Main Authors: Gong, Jinlong, Ojifinni, Rotimi A., Kim, Tae S., Stiehl, James D., McClure, Sean M., White, John M., Mullins, C. Buddie
Format: Article
Language:English
Subjects:
Atomic oxygen
Carbon dioxide
Carbon monoxide
Low temperature
Moisture effects
Molecular beams
Oxidation
Oxygen atoms
Precursors
Reaction mechanisms
Ultrahigh vacuum
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:This paper presents results of an investigation of low-temperature CO oxidation and the role of moisture on an atomic oxygen covered Au(111) surface by employing molecular beam scattering techniques under ultrahigh vacuum (UHV) conditions. The effect of atomic oxygen precoverage on CO oxidation was examined at sample temperatures as low as 77 K. Prompt CO2 production was observed when the CO beam impinges on the sample followed by a rapid decay of CO2 production in all cases. At oxygen precoverages above 0.5 ML, CO2 production decreases with increasing oxygen precoverage primarily due to the decrease in CO uptake. CO oxidation at 77 K goes through a precursor mediated reaction mechanism, where CO is in a precursor or trapped state and oxygen atoms are in a chemisorbed state. The role of adsorbed water was studied by using isotopically labeled water [H218O] to distinguish the oxygen species from that used in oxygen atom exposures [16O]. Evidence is presented that shows activated water or OH groups formed from water can directly participate in oxidizing CO on an atomic oxygen covered Au(111) surface.
ISSN:1022-5528
1572-9028
DOI:10.1007/s11244-007-0278-8