Electron-hole pair effects in hydrogen dissociation on metals
Abstract
Dissociative sticking, as the prototype of a catalytic reaction, has been extensively investigated both theoretically and experimentally. On the basis of a recently proposed fully quantum mechanical model to describe inelasticity in dissociative sticking of a diatomic molecule, we treat the effect of electron-hole pair (ehp) excitations both in activated and non activated sticking of H_2, in its ground vibrational state, on metals. In the former case the substrate is parameterized to describe Cu(111), in the latter Pd(100). We observe the following results for both systems. The main contribution to sticking of the ehp inelasticity is a dynamical polarization of the adiabatic electronic system with no energy loss to the ehp, which favors sticking compared with the elastic description. The dissipative effect of explicitly exciting ehp is less important. The ehp sticking coefficient of D2 is significantly smaller than that of H2 for low incoming molecule translational energies.
- Publication:
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APS March Meeting Abstracts
- Pub Date:
- March 2002
- Bibcode:
- 2002APS..MARW20010B