Interactions between oxygen and carbon monoxide on a Pd(111) surface

Conrad, H.; Ertl, G.; Küppers, J.

doi:10.1016/0039-6028(78)90101-2

Cited by 360 publications

(232 citation statements)

References 24 publications

Supporting

Mentioning

207

Contrasting

Order By: Relevance

“…It was suggested that the transformation was due to coadsorption of residual hydrogen or CO in the vacuum system [22]. A similar (2×2) → (√3×√3)R30 o transformation was observed in our experiments upon addition of hydrogen above 150 K [23].…”

Section: Introductionsupporting

confidence: 85%

Interactions of oxygen and hydrogen on Pd(111) surface

et al. 2008

View full text Add to dashboard Cite

The coadsorption and interactions of oxygen and hydrogen on Pd(111) was studied by scanning tunneling microscopy and density functional theory calculations. In the absence of hydrogen oxygen forms a (2×2) ordered structure. Coadsorption of hydrogen leads to a structural transformation from the (2×2) to a (√3×√3)R30 o structure. In addition to this transformation, hydrogen enhances the mobility of oxygen. To explain these observations, the interaction of oxygen and hydrogen on Pd(111) was studied within the density functional theory. In agreement with the experiment the calculations find a total energy minimum for the oxygen (2×2) structure. The interaction between H and O atoms was found to be repulsive and short ranged, leading to a compression of the O islands from (2×2) to (√3×√3)R30 o ordered structure at high H coverage. The computed energy barriers for the oxygen diffusion were found to be reduced due to the coadsorption of hydrogen, in agreement with the experimentally observed enhancement of oxygen mobility. The calculations also support the finding that at low temperatures the water formation reaction does not occur on Pd(111).

show abstract

Section: Introductionsupporting

confidence: 85%

Interactions of oxygen and hydrogen on Pd(111) surface

et al. 2008

View full text Add to dashboard Cite

show abstract

“…Following recent work the ͑2 ϫ 1͒ phase is a pure oxygen structure; 7,10 a mixed ͑2 ϫ 1͒O / CO structure, with one O atom and one CO molecule per unit cell, which was assumed in the older work, 5,11 can almost certainly be ruled out. DFT calculations have shown that the compression of the oxygen layer is connected with a lowering of the O binding energy, from 1.15 eV in the ͑2 ϫ 2͒O structure to 0.84 eV in the ͑2 ϫ 1͒O structure.…”

Section: Resultsmentioning

confidence: 99%

“…5 In the absence of CO, oxygen forms a ͑2 ϫ 2͒O structure. Adsorption of CO on this phase ͑at a lowered temperature, e.g., at 200 K, to avoid immediate reaction to give CO 2 ͒ leads to phase transitions, first to a ͑ ͱ 3x ͱ 3͒R30°O structure, then to a ͑2 ϫ 1͒O structure.…”

Section: Introductionmentioning

confidence: 99%

Enhanced reactivity of adsorbed oxygen on Pd(111) induced by compression of the oxygen layer

et al. 2005

Self Cite

View full text Add to dashboard Cite

The reaction between O atoms and CO molecules on Pd͑111͒ was investigated by scanning tunneling microscopy ͑STM͒. CO was dosed on the ͑2 ϫ 2͒O-covered surface at temperatures between 100 and 190 K, and the structure changes were monitored by STM. CO adsorption causes compression of the ͑2 ϫ 2͒O overlayer into islands of the ͑2 ϫ 1͒O structure, followed by reaction of the O atoms to give CO 2 . The ͑2 ϫ 2͒O overlayer does not react with CO at temperatures up to 180 K, whereas the ͑2 ϫ 1͒O phase reacts at temperatures as low as 136 K. The analysis of the reaction kinetics reveals an activation energy for the O + CO reaction of 0.4 eV and a reaction order of 1 with respect to the O coverage.

show abstract

“…19 Note that Pd(111) [57][58][59] and Pd nanoclusters on MgO 60 display a similar behavior. The maximum of CO 2 production is observed at ∼470 K and estimated to 0.03 CO 2 per cluster surface Pt atom.…”

Section: Introductionmentioning

confidence: 95%