Trapping Nitric Oxide by Surface Hydroxyls on Rutile TiO2(110)

S.-C. Li, P. Jacobson, S.-L. Zhao, X.-Q. Gong, U. Diebold

Department of Physics and Engineering Physics, Tulane University, New Orleans, LA, 70118, U.S.A.
National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, P. R. China.
Institut für Angewandte Physik, Technische Universität Wien, 1040 Wien, Austria
State Key Laboratory of Chemical Engineering, Centre for Computational Chemistry and Research Institute of Industrial Catalysis, East China University of Science and Technology, Shanghai 200237, P. R. China

J. Phys. Chem. C 116 (2012) 1887-1891

Hydroxyls are omnipresent on oxide surfaces under ambient conditions. While they unambiguously play an important role in many catalytic processes, it is not well-understood how these species influence surface chemistry at atomic scale. We investigated the adsorption of nitric oxide (NO) on a hydroxylated rutile TiO2(110) surface with scanning tunneling microscopy (STM), X-ray/ultraviolet photoemission spectroscopy (XPS/ UPS), and density functional theory (DFT) calculations. At room temperature adsorption of NO is only possible in the vicinity of a surface hydroxyl, and leads to a change of the local electronic structure. DFT calculations confirm that the surface hydroxyl-induced excess charge is transferred to the NO adsorbate, which results in an electrostatic stabilization of the adsorbate and, consequently, a significantly stronger bonding.

Corresponding author: Shao-Chun Li. Reprints also available from Ulrike Diebold (diebold at iap_tuwien_ac_at).

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