In this work we propose a new force field for modelling of adsorption of CO2, N2, O2 and Ar in all silica and Na+ exchanged Si–Al zeolites. The force field has a standard molecular-mechanical functional form with electrostatic and Lennard-Jones interactions satisfying Lorentz–Berthelot mixing rules and thus has a potential for further extension in terms of new molecular types. The parameters fo...

In a previous work we studied the influence of heat treatment on the molecular sieve properties of activated carbons prepared by chemical activation of lignin [1]. The thermal treatment modified the porous structure of the activated carbons, giving rise to solids that separate C6H6 from C6H12, CO2 from CH4 and O2 from N2 with a relative high selectivity. However, the heat treatment drastically ...

Preparation of heterogeneous catalysts with active ferrous centers is of great significance for industrial and environmental catalytic processes. Nanostructured carbon materials (NCM), which possess free-flowing π electrons, can coordinate with transition metals, provide a confinement environment for catalysis, and act as potential supports or ligands to construct analogous complexes. However, ...

A photosensitized BiOCl catalyst was found to be effective for photocatalytic water purification and air remediation under visible light irradiation (λ > 420 nm). Prepared by a solvothermal method, the BiOCl crystals possessed a 3D hierarchical spherical structure with the highly active facets exposed. When sensitized by Rhodamine B (RhB), the photocatalyst system was more active than N-doped T...

Infrared reflection-absorption spectroscopic measurements have been performed on single-wall carbon nanotubes (SWNTs), cleaned by heating to approximately 500 degrees C in vacuo, during exposure to pure 16O2 or 18O2 at room temperature and at pressures of up to approximately 630 Torr. No vibrational signature of any form of adsorbed O is detected. However, structure is seen which is very simila...

Studies show that the rate of CO oxidation on Pt-group metals at temperatures between 450 and 600 K and pressures between 1 and 300 Torr increases markedly with an increase in the O2/CO ratio above 0.5. The catalytic surfaces, formed at discrete O2/CO ratios >0.5, exhibit rates 2–3 orders of magnitude greater than those rates observed for stoichiometric reaction conditions and similar reactant ...

A novel manganese dioxide–hydrogen peroxide (MnO2–H2O2) system was developed for effective Arsenic (As) removal. Under the specified conditions of no external mechanical stirring, a trace H2O2 concentration 0.015 wt%, and MnO2 25 mg/L, high removal efficiency (88%) As (100 µg/L) achieved by MnO2–H2O2 within 30 min, which differs from conventional adsorption processes that require stirring arsen...

In this work, Ho2O3 nanosheets were synthesized by a hydrothermal method. A series of Sr-modified (Sr-Ho2O3-NS) with Sr/Ho molar ratio between 0.02 and 0.06 prepared via an impregnation These catalysts characterized several techniques such as XRD, N2 adsorption, SEM, TEM, XPS, O2-TPD (temperature-programmed desorption), CO2-TPD, they studied respect to their performances in the oxidative coupli...

By using the first-principles density functional theory, we calculate the partial charge densities and STM images for the intradimer di-σ and interdimer end-bridge adsorption configurations of ethylene on Ge(001). Our simulated STM images show the effects of ethylene adsorption and clarify that, although STM images and surface structures evolve as the adsorption sites of ethylene on Ge(001), th...