| Autor: |
Vesselli E; Physics Department and CENMAT, University of Trieste, via Valerio 2, I-34127 Trieste, Italy., Rizzi M; Physics Department, University of Trieste, Strada Costiera 11, I-34151 Trieste, Italy., Furlan S; Physics Department, University of Trieste, Strada Costiera 11, I-34151 Trieste, Italy., Duan X; Department of Physics, Ningbo University, 818 Fenghua Road, Jiangbei District, 315211 Ningbo, People's Republic of China., Monachino E; Physics Department and CENMAT, University of Trieste, via Valerio 2, I-34127 Trieste, Italy., Dri C; Physics Department and CENMAT, University of Trieste, via Valerio 2, I-34127 Trieste, Italy., Peronio A; Physics Department and CENMAT, University of Trieste, via Valerio 2, I-34127 Trieste, Italy., Africh C; IOM-CNR Laboratorio TASC, Area Science Park, S.S. 14 km 163.5, Trieste I-34149, Basovizza, Italy., Lacovig P; Elettra-Sincrotrone Trieste S.C.p.A., Area Science Park, S.S. 14 km 163.5, I-34149 Trieste, Italy., Baldereschi A; Physics Department, University of Trieste, Strada Costiera 11, I-34151 Trieste, Italy., Comelli G; Physics Department and CENMAT, University of Trieste, via Valerio 2, I-34127 Trieste, Italy., Peressi M; Physics Department, University of Trieste, Strada Costiera 11, I-34151 Trieste, Italy. |
| Abstrakt: |
The adsorption energy of carbon monoxide on Ni ad-islands and ultra-thin films grown on the Cu(110) surface can be finely tuned via a complex interplay among diffusion, site change mechanisms, and coverage effects. The observed features of CO desorption can be explained in terms of migration of CO molecules from Cu to Ni islands, competition between bridge and on-top adsorption sites, and repulsive lateral adsorbate-adsorbate interactions. While the CO adsorption energy on clean Cu(110) is of the order of 0.5 eV, Ni-alloying allows for its controlled, continuous tunability in the 0.98-1.15 eV range with Ni coverage. Since CO is a fundamental reactant and intermediate in many heterogeneous catalytic (electro)-conversion reactions, insight into these aspects with atomic level detail provides useful information to potentially drive applicative developments. The tunability range of the CO adsorption energy that we measure is compatible with the already observed tuning of conversion rates by Ni doping of Cu single crystal catalysts for methanol synthesis from a CO 2 , CO, and H 2 stream under ambient pressure conditions. |
