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Tetraoxygen on Reduced TiO 2 ( 110 ) : Oxygen Adsorption and Reactions with Bridging Oxygen Vacancies

2008; American Physical Society; Volume: 100; Issue: 19 Linguagem: Inglês

10.1103/physrevlett.100.196102

1092-0145

Greg A. Kimmel, Nikolay G. Petrik,

Advanced Photocatalysis Techniques

Oxygen adsorption on reduced TiO2(110) is investigated using temperature programmed desorption and electron-stimulated desorption. At low temperatures, 2 O(2) molecules can be chemisorbed in each oxygen vacancy. These molecules do not desorb upon annealing to 700 K. Instead, for 200 K<T<400 K, the 2 O(2) convert to another species, which has four oxygen atoms, i.e., tetraoxygen, that decomposes at higher temperatures. In contrast, when only 1 O(2) is adsorbed in an oxygen vacancy, the molecule dissociates upon annealing above ~150 K to heal the vacancy in agreement with previous results.