Oxidation and Reduction of TiOx Thin Films on Pd(111) and Pd(100)

M H Farstad; D Ragazzon; M D Strømsheim; J Gustafson; A Sandell; A Borg

doi:10.1021/acs.jpcb.7b06282

Oxidation and Reduction of TiO_x Thin Films on Pd(111) and Pd(100)

J Phys Chem B. 2018 Jan 18;122(2):688-694. doi: 10.1021/acs.jpcb.7b06282. Epub 2017 Sep 7.

Authors

M H Farstad¹, D Ragazzon², M D Strømsheim¹, J Gustafson², A Sandell², A Borg³

Affiliations

¹ Department of Chemical Engineering, Norwegian University of Science and Technology , NO-7491 Trondheim, Norway.
² Department of Physics and Astronomy, Uppsala University , P.O. Box 530, SE-75121 Uppsala, Sweden.
³ Department of Physics, Norwegian University of Science and Technology , NO-7491 Trondheim, Norway.

PMID: 28825490
DOI: 10.1021/acs.jpcb.7b06282

Abstract

Thin films of TiO_x on Pd(100) and Pd(111) have been investigated with respect to their properties after oxidation and reduction cycles. High-resolution photoemission spectroscopy (HRPES) and low energy electron diffraction (LEED) have been applied to characterize the thin film oxidation states and structure before and after oxidation and reduction under ultrahigh vacuum conditions. Fully oxidized TiO₂ films were formed on both surfaces. These structures display Moiré patterns in LEED, in one dimension for Pd(100) and in two dimensions for Pd(111), and they have previously not been reported for TiO₂/Pd. The oxidation process causes strong reduction in the interaction between the oxide thin film and the Pd substrate, most significantly for Pd(111). Reversible oxidation/reduction cycling of TiO_x thin films on Pd(111) and Pd(100) was possible.

Publication types

Research Support, Non-U.S. Gov't