Li W X, Osterlund L, Vestergaard E K, Vang R T, Matthiesen J, Pedersen T M, Laegsgaard E, Hammer B, Besenbacher F
Interdisciplinary Nanoscience Center, Center for Atomic-scale Materials Physics, and Department of Physics and Astronomy, University of Aarhus, DK 8000 Aarhus C, Denmark.
Phys Rev Lett. 2004 Oct 1;93(14):146104. doi: 10.1103/PhysRevLett.93.146104. Epub 2004 Sep 29.
Using scanning tunneling microscopy and temperature programmed desorption we investigate the Pt(110) surface under strongly oxidizing conditions involving either high-pressure O2 or atomic oxygen exposure. At low temperatures, only disordered Pt oxide structures are observed. After annealing ordered surface oxide islands are observed to coexist with a highly stable reconstructed (12x2)-O chemisorption structure. From density functional theory calculations a model for the surface oxide phase is revealed. The phase is found to be metastable, and its presence is explained in terms of stabilizing defects in the chemisorption layer and reduced Pt mobility.
