title: Fingerprints of energy dissipation for exothermic surface chemical reactions: O2 on Pd(100).
abstract: We present first-principles calculations of the sticking coefficient of O2 at Pd(100) to assess the effect of phononic energy dissipation on this kinetic parameter. For this, we augment dynamical simulations on six-dimensional potential energy surfaces (PESs) representing the molecular degrees of freedom with various effective accounts of surface mobility. In comparison to the prevalent frozen-surface approach, energy dissipation is found to qualitatively affect the calculated sticking curves. At the level of a generalized Langevin oscillator model, we achieve good agreement with experimental data. The agreement is similarly reached for PESs based on two different semi-local density-functional theory functionals. This robustness of the simulated sticking curve does not extend to the underlying adsorption mechanism, which is predominantly directly dissociative for one functional or molecularly trapped for the other. Completely different adsorption mechanisms therewith lead to rather similar sticking curves that agree equally well with the experimental data. This highlights the danger of the prevalent practice to extract corresponding mechanistic details from simple fingerprints of measured sticking data for such exothermic surface reactions.
authors.affiliation: Chair for Theoretical Chemistry and Catalysis Research Center, Technische Universität München, Lichtenbergstr. 4, D-85747 Garching, Germany.
authors.forename: Vanessa J
authors.initials: VJ
authors.lastname: Bukas
authors.affiliation: Chair for Theoretical Chemistry and Catalysis Research Center, Technische Universität München, Lichtenbergstr. 4, D-85747 Garching, Germany.
authors.forename: Shubhrajyoti
authors.initials: S
authors.lastname: Mitra
authors.affiliation: Gorlaeus Laboratories, Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands.
authors.forename: Jörg
authors.initials: J
authors.lastname: Meyer
authors.affiliation: Chair for Theoretical Chemistry and Catalysis Research Center, Technische Universität München, Lichtenbergstr. 4, D-85747 Garching, Germany.
authors.forename: Karsten
authors.initials: K
authors.lastname: Reuter