A theoretical analysis of small Pt particles on rutile TiO$ 2$110 surfaces - Condensed Matter > Strongly Correlated ElectronsReport as inadecuate




A theoretical analysis of small Pt particles on rutile TiO$ 2$110 surfaces - Condensed Matter > Strongly Correlated Electrons - Download this document for free, or read online. Document in PDF available to download.

Abstract: The adsorption profiles and electronic structures of Pt$ n$ n = 1-4clusters on stoichiometric, reduced and reconstructed rutile TiO$ 2$110surfaces were systematically studied using on site d-d Coulomb interactioncorrected hybrid density functional theory calculations. The atomic structureof small Pt cluster adsorbates mainly depend on the stoichiometry of thecorresponding titania support. The cluster shapes on the bulk terminated idealsurface look like their gas phase low energy structures. However, for instance,they get significantly distorted on the reduced surfaces with increasing oxygenvacancies. On non-stoichiometric surfaces, Pt-Ti coordination becomes dominantin the determination of the adsorption geometries. The electronic structure ofPt$ n$-TiO$ 2$110 systems can not be correctly described by pure DFT methods,particularly for non-stoichiometric cases, due to the inappropriate treatmentof the correlation for $d$ electrons. We performed DFT+U calculations to give areasonable description of the reconstructed rutile 110 surface. Pt clustersinduce local surface relaxations that influence band edges of titania support,and bring a number of band-gap states depending on the cluster size.Significant band gap narrowing occurs upon Pt$ n$-surface interaction due toadsorbate driven states on the bulk terminated and reduced surfaces. On theother hand, they give rise to a band gap widening associated to partialreoxidation of the reconstructed surface. No metallization arises even forPt$ 4$ on rutile.



Author: Veysel Celik, Hatice Unal, Ersen Mete, Sinasi Ellialtioglu

Source: https://arxiv.org/



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