HREELS investigations of adsorbed hydrogen on transition metals

Chemisorption of hydrogen on the missing-row Pt(110)-(1 × 2) surface

“…Our results confirm an HREELS experiment of H/ Pt(110) [14] indicating a 2-fold bridge site at low coverage.…”

“…Recently, we reported an atypical bonding geometry of the so-called b 2 -state at a coverage of 0.5 hydrogen atoms per 1 · 1 unit cell (0.5 ML) [9]: Contrary to the general expectation [10,11] and to proposals specific to the Pt(110) surface [12][13][14][15], hydrogen adsorbs in the low coordinated short bridge site on top of the outermost platinum rows. The current paper includes both, the former low coverage results and additionally experimental and theoretical investigations for higher coverages up to saturation.…”

“…by a substantial temperature and coverage dependent substrate response (see below), and the strong anisotropy of the surface complicate the interpretation of TPD spectra, of course. We note that our crystal has an extremely low miscut, a parameter which could also distinguish the various earlier experiments [2,[12][13][14][15]20]. Lower heating rates than 1 K/s would be interesting, but were not feasible with our current experimental setup.…”

Analysis of temperature effects on hydrogen and OH adsorption on Pt(1 1 1), Pt(1 0 0) and Pt(1 1 0) by means of Gibbs thermodynamics

“…Then, this thermodynamic data can be used to calculate the OH adsorption pseudocapacity, by using Eqs. (43) and (44), and these results can be used to subtract the contribution of OH adsorption to the experimental voltammograms, and to obtain in this way the hydrogen coverages from the integration of the thus corrected voltammetric curves. Finally, the thermodynamic parameters of hydrogen adsorption can then be obtained by the application of the generalized isotherm (Eqs.…”

Direct estimation of surface pressures by hydrogen adsorbates on platinum surfaces in perchloric acid

“…It is known that cyclic voltammetry of Pt(110) prepared by flame annealing also shows surface reconstruction after immersion in acid electrolytes [57]. However, surface atomic mobility induced by potential cycling, yields a less reconstructed Pt(110) surface [58]. The sites nearby the missing row model have been analysed as (111) × (110) stepped surfaces and the reconstructed Pt(110) surface emerges as a particular case of these stepped surfaces [15,55].…”