Electronic and chemical properties of mixed-metal oxides: adsorption of SO2 on SrTiO3(0 0 1)

The structural, electronic, and chemical properties of the SrTiO3(0 0 1) surface were examined by means of first-principles density-functional (DF) slab calculations (LDA, GGA Perdew–Burke–Ernzerhoff functional). In qualitative terms, the LDA and GGA predict similar structural relaxations for the SrTiO3(0 0 1) system. DF results for bulk SrTiO3 and SrTiO3(0 0 1) illustrate the important effects that metal ↔ oxygen ↔ metal interactions can have on the electronic and chemical properties of a mixed-metal oxide. A big increase in the electron density of Ti is found when going from TiO2 to SrTiO3. This phenomenon can easily explain why SrTiO3 is a much better DeSOx catalyst than pure TiO2.