The atomic geometry of oxygen-rich Ru(0001) surfaces: coexistence of (1 x 1)O and RuO2(110) domains

Employing the technique of low energy electron diffraction (LEED) in combin ation with density functional theory (DFT) calculations, we determined the atomic geometry of the oxygen-rich Ru(0001) surface, which was recently sho wn to be extraordinarily active in the conversion of CO towards CO2. The ox ygen-rich Ru(0001) surface consists of areas (some 10 mum wide) covered by a (1 x 1)O overlayer in coexistence with ultrathin (10-20 Angstrom) patches of ruthenium dioxide RuO2 in (110) orientation. The oxide surface structur e is characterized by a bulk-truncated RuO2(110) surface which is terminate d by bridging oxygen rows. (C) 2000 Elsevier Science B.V. All rights reserv ed.