Structure dependence of molecular reactions on surfaces
2018
The research presented in this thesis makes use of small
molecules (as H2 , D2 and O2 ) on well-defined single crystal surfaces (flat
Pt(111), flat Cu(211) and curved Pt(111)) to elucidate the role of surface
structure and degrees of freedom in the reactant in specific surface
reactions. For D2 on Pt(111), we find at most a very weak signature of
geometric corrugation at large polar angles. For D2 on Cu, we find an
anomalous reduced dissociative sticking probability for the stepped Cu(211)
surface compared to Cu(111). For hydrogen on curved Pt(111), the HD formation
increases linearly with the step density at low incident energy. A surface
reconstruction on curved Pt(111) surface is observed on both A- and B-step
side when the crystal is annealed at 1200 K. For O2 on curved Pt(111), at low
incident energy, steps dominate reactivity by providing an indirect dynamical
trapping mechanism. At higher impact energy, a direct chemisorption mechanism
dominates. The step facet favors molecules impacting with their internuclear
axis parallel to its surface.
Keywords:
- Correction
- Cite
- Save
- Machine Reading By IdeaReader
0
References
2
Citations
NaN
KQI