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Following our strategy to analyze the metal–support interaction, we present periodic DFT calculations for adsorption of metal atoms on a perfect rutile TiO2(110) surface (at low coverage, θ = 1/3) to investigate the interaction of an individual metal atom, M, with TiO2 and its consequence on the coadsorption of H and CO over M/TiO2. M under investigation varies in a systematic way from K to Zn. It is found that the presence of the support decreases or increases the strength of M–H or M–CO interaction according to the nature of M. The site of the adsorption for H and the formation of HCO/M also depend on M. From the left- to the right-hand side of the period, C and O both interact while O progressively detaches from M. On the contrary, for M = Fe–Cu, CO dissociation is more likely to happen. For CO and H coadsorption, two extreme cases emerge: For Ni, the hydrogen adsorbed should easily move on the support and CO dissociation is more likely. For Ti or Sc, H is easily coadsorbed with CO on the metal and CO hydrogenation could be the initial step. [ABSTRACT FROM AUTHOR]

We performed periodic DFT calculations for adsorption of metal atoms on a perfect rutile TiO(110) surface (at low coverage, θ = 1/3) to investigate the interaction of an individual metal atom with TiO and to compare it with a study previously done on MgO(100). We considered partial period of Mendeleev's table from K to Zn. The overall evolution of the adsorption energies shows two maxima as for MgO(100). Two main differences, however, exist: the adsorption energy is much stronger and the first maximum is enhanced relative to the second one. This is attributed to the reducibility of the surface titanium cation. When the adsorbed metal is electropositive, it is oxidized under adsorption transferring electrons to titanium cations. We present the effect of introducing a Hubbard term to the gradient-corrected approximation band-structure Hamiltonian (GGA + U). The introduction of a reasonable Hubbard correction preserves the trends and allows localizing the electron of the reduction on Ti atoms in the near surface region. Finally, our results conclude that for heavier M atoms of the period, insertion is energetically favored relative to adsorption. [ABSTRACT FROM AUTHOR]