Modeling the adsorption and dissociation of CO on transition metal surfaces

Understanding CO-stripping mechanism from NiUPD/Pt(110) in view of the measured nickel formal partial charge number upon underpotential deposition on platinum surfaces in sulphate media

“…As stated above, the presence of peak 1 for (CO ad + Ni UPD )-stripping experiment, the coulometry of which is close to that for CO ad -stripping voltammograms in the absence of nickel in solution, is a strong evidence that after peak 2, the CO-adlayer has been rebuilt over the Pt(1 1 0)-(1 × 2) surface freed from any Ni UPD atoms. The fast CO ad diffusion coefficient on nickel substrates, as monitored in UHV conditions for nickel crystals [43][44][45][46][47] or for Ni/W(1 1 0) surfaces [48], is consistent with such scenario. In addition, CO ad displays a greater stability over platinum surface, at least for singles crystals in the (1 1 1) orientation in UHV conditions [48].…”

“…The fast CO ad diffusion coefficient on nickel substrates, as monitored in UHV conditions for nickel crystals [43][44][45][46][47] or for Ni/W(1 1 0) surfaces [48], is consistent with such scenario. In addition, CO ad displays a greater stability over platinum surface, at least for singles crystals in the (1 1 1) orientation in UHV conditions [48]. The conjunction of these two findings is consistent with the possibility for CO ad to simply diffuse (superficially) from Ni UPD sites to the neighbouring free Pt(1 1 0) sites.…”

Nickel-underpotential deposition on Pt(110) in sulphate-containing media

“…Nickel submonolayer on Pt(1 1 0) exhibits remarkable properties for CO-oxidation, maybe due to the CO higher mobility over nickel than over platinum, as already observed under UHV-conditions [24][25][26][27][28]. Such an interesting behaviour of nickel submonolayer as already been reported by Pavao et al for Ni/W(1 1 0) [29]. Thanks to the possibly high CO-mobility over nickel, its oxidation would occur at the adjacent nickel and platinum sites, probably by synergistic effect between nickel and platinum atoms.…”

Quantum Monte Carlo study of the CO interaction with a dimer model surface for Cr(110)

“…El Akramine et al It is worth noting that the large 1.9 eV energy difference between the two geometries agrees well with semiempirical results based on the Hu¨ckel Hamiltonian [11]. The tilted/near-parallel configuration is a consequence of strong p and 5s donation bonds whose antibonding counterparts are empty [1,3]. The DMC energy difference is considerably larger than that obtained in our ab initio HF study [4].…”

“…Evaluating quantitatively the interaction energy between a gas molecule and a TM surface, despite its importance, still presents computational difficulties; for recent reviews see [1,2]. Much effort has been devoted to the investigation of the specific behaviour of each TM and the influence of the surface structure of the metal on the interaction with a diatomic molecule (see, e.g., [3]). …”