In this Letter we show that sequences of adsorbate-induced shifts of surface core level (SCL) x-ray photoelectron spectra contain profound information on surface changes of electronic structure and reactivity. Energy shifts and intensity changes of time-lapsed spectral components follow simple rules, from which adsorption sites are directly determined. Theoretical calculations rationalize the r...

The adsorption of Li and K atoms on the (001) surface of tungsten is found to exhibit remarkable differences in the surface core-level shifts (SCLS) of the W 4f level and in adsorbate-induced changes of the transition temperature of the substrate surface reconstruction. Density-functional theory calculations suggest that these results reflect mainly the different bonding geometry of the adatoms...

Molecular simulations corroborate the existence of the disputed window effect, i.e., an increase in diffusion rate by orders of magnitude when the alkane chain length increases so that the shape of the alkane is no longer commensurate with that of a zeolite cage. This window effect is shown to be characteristic for molecular sieves with pore openings that approach the diameter of the adsorbate....

A thermodynamic study of carbon dioxide adsorption on a zeolite-templated carbon (ZTC), a superactivated carbon (MSC-30) and an activated carbon (CNS-201) was carried out at temperatures from 241 to 478 K and pressures up to 5.5 106 Pa. Excess adsorption isotherms were fitted with generalized Langmuir-type equations, allowing the isosteric heats of adsorption and adsorbed-phase heat capacities ...

isotherm equation is one of the important scientific bases for adsorbent selection. there are different isotherms that do not account for an adsorbate, different chemisorption geometries on the nanoporous surface. it is interesting to introduce a general isotherm, which considers different chemisorption geometries of an adsorbate on nanoporous surfaces. in this study, an isotherm for non-dissoci...

Quantitative analytical applications of surface-enhanced Raman spectrometry (SERS) on colloidal substrates are hindered by the experimental difficulties in measuring intensities with precision comparable to that of state-of-theart spectrochemical techniques. Several factors, both adsorbateand substrate-dependent, contribute to the poor reproducibility of SERS. Since the observed enhancement fac...

In this thesis, nuclear magnetic resonance (NMR) spectroscopy of noble gas atoms and methane molecule is applied to the structure studies of solid microporous materials (molecular sieves). This is an indirect method, where changes to the spectral parameters (i.e. isotropic and anisotropic nuclear shielding tensors) of the adsorbate induced by the investigated environment are measured at variabl...