Surface science studies of model fuel cell electrocatalysts

http://myweb.clemson.edu/~daw/D_reprints/MatSciRep.v9p251y93.pdf

The embedded-atom method: a review of theory and applications

Hydrogen (H2) was produced by aqueous-phase reforming of biomass-derived oxygenated hydrocarbons at temperatures near 500 kelvin over a tin-promoted Raney-nickel catalyst. The performance of this non-precious metal catalyst compares favorably with that of platinum-based catalysts for production of hydrogen from ethylene glycol, glycerol, and sorbitol. The addition of tin to nickel decreases the rate of methane formation from C-O bond cleavage while maintaining the high rates of C-C bond cleavage required for hydrogen formation.

/pdf/raney-ni-sn-catalyst-for-h2-production-from-biomass-derived-44vm8v6ydj.pdf

Raney Ni-Sn Catalyst for H2 Production from Biomass-Derived Hydrocarbons

Evaluation of random forest and adaboost tree-based ensemble classification and spectral band selection for ecotope mapping using airborne hyperspectral imagery

The role of surface stress in reconstruction, epitaxial growth and stabilization of mesoscopic structures

A method is described for quantitative analysis of low-energy-electron diffraction (LEED) intensity-energy spectra by comparison of experimental spectra with spectra calculated using a dynamic theory of LEED. The method involves a minimization of the variance of the fit between experimental and calculated spectra as a function of the calculational variables, both structural and nonstructural, leading to determination of optimum parameter values. Correlation between the variables is taken into account. The method is applied to extensive, new experimental LEED data for Pt(111). It is shown quantitatively that the variance of the fit depends strongly on the value of a single structural variable, ${d}_{\ensuremath{\perp}}$, the first interlayer spacing, but weakly on the values of three nonstructural variables, ${V}_{0}$, the inner potential, ${V}_{\mathrm{im}}$, the absorption potential, and ${\ensuremath{\Theta}}_{D}$, the Debye temperature. The analysis leads to an optimum value of ${d}_{\ensuremath{\perp}}=2.29$ \AA{}, corresponding to a 1% expansion of the first layer spacing, with an estimated error of \ifmmode\pm\else\textpm\fi{}0.1 \AA{}. This result is in good agreement with the earlier studies of Kesmodel and co-workers.

Quantitative analysis of low-energy-electron diffraction: Application to Pt(111)

The missing-row model for the reconstructed Pt(110)−(1 × 2) surface: A leed intensity analysis showing multilayer distortions

Complementary studies of the Cu(110) surface have been carried out by means of low-energy electron diffraction and high-energy ion scattering. The results obtained from the use of the two techniques are in acceptable agreement and indicate that the interlayer spacings in the Cu(110) surface exhibit a damped, oscillatory deviation from the bulk value, in qualitative agreement with the predictions of Landman, Hill, and Mostoller.

Oscillatory Relaxation of the Cu(110) Surface

LEED study of the Pt(110)-(1 × 2) surface

Surface-extended x-ray-absorption fine-structure studies on the Ni(111)-c(4\ifmmode\times\else\texttimes\fi{}2)-CO system show that CO adsorbs in threefold-coordinated hollow sites. This result is in conflict with the adsorption-site determination via molecular vibrational frequencies, which for this system led to an assignment of a bridge site.

D.L. Adams

Papers

Quantitative analysis of low-energy-electron diffraction: Application to Pt(111)

The missing-row model for the reconstructed Pt(110)−(1 × 2) surface: A leed intensity analysis showing multilayer distortions

Oscillatory Relaxation of the Cu(110) Surface

LEED study of the Pt(110)-(1 × 2) surface

Threefold-coordinated hollow adsorption site for Ni(111)-c(4 x 2)-CO: A surface-extended x-ray-absorption fine-structure study.