Regensburg 2019 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 26: Frontiers of Electronic-Structure Theory: Focus on the Interface Challenge III (joint session O/CPP/DS/TT)
TT 26.3: Vortrag
Dienstag, 2. April 2019, 11:15–11:30, H9
Interplay of quantum nuclear fluctuations and the electronic structure of the cyclohexane/Rh(111) interface — •Karen Fidanyan and Mariana Rossi — Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, Berlin
Cyclohexane (C6H12) adsorbed on metal surfaces can participate in catalytic dehydrogenation reactions, which show good potential for hydrogen storage. It has been observed experimentally that C6H12 adsorbed on the Rh(111) surface shows an isotope effect on the work function change and the adsorption energy upon deuteration [1]. The physical origin of this puzzling isotope effect on the electronic structure has not been fully resolved. We employ density-functional theory (PBE functional with van der Waals corrections) and ab initio path-integral molecular dynamics at 150 K to characterize the underlying physics of this phenomenon. We perform these simulations almost at classical-nuclei cost by making use of the spatially-localized ring-polymer contraction scheme proposed in Ref. [2]. The harmonic approximation to zero-point-energy in the adsorption energy is not able to capture the isotope effects observed experimentally. We thus include anharmonic corrections through the dynamics and identify the temperature-dependent electronic level broadening and renormalization due to the interaction with phonons in this system.
[1] T. Koitaya and J. Yoshinobu, Chem. Rec. 14 848-856 (2014).
[2] Y. Litman, D. Donadio, M. Ceriotti and M. Rossi, J. Chem. Phys. 148 102320 (2018).