High chemical activity of a perovskite surface: reaction of CO with Sr(3)Ru(2)O(7).
作者信息
Stöger Bernhard, Hieckel Marcel, Mittendorfer Florian, Wang Zhiming, Fobes David, Peng Jin, Mao Zhiqiang, Schmid Michael, Redinger Josef, Diebold Ulrike
机构信息
Institute of Applied Physics, Vienna University of Technology, Wiedner Hauptstraße 8-10, A-1040 Vienna, Austria.
Institute of Applied Physics, Vienna University of Technology, Wiedner Hauptstraße 8-10, A-1040 Vienna, Austria and Center for Computational Materials Science, Vienna University of Technology, Gußhausstraße 25-25a, A-1040 Vienna, Austria.
出版信息
Phys Rev Lett. 2014 Sep 12;113(11):116101. doi: 10.1103/PhysRevLett.113.116101. Epub 2014 Sep 10.
Adsorption of CO at the Sr(3)Ru(2)O(7)(001) surface was studied with low-temperature scanning tunneling microscopy (STM) and density functional theory. In situ cleaved single crystals terminate in an almost perfect SrO surface. At 78 K, CO first populates impurities and then adsorbs above the apical surface O with a binding energy E(ads)=-0.7 eV. Above 100 K, this physisorbed CO replaces the surface O, forming a bent CO(2) with the C end bound to the Ru underneath. The resulting metal carboxylate (Ru-COO) can be desorbed by STM manipulation. A low activation (0.2 eV) and high binding (-2.2 eV) energy confirm a strong reaction between CO and regular surface sites of Sr(3)Ru(2)O(7); likely, this reaction causes the "UHV aging effect" reported for this and other perovskite oxides.
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