CO2 adsorption in LiY and NaY at high temperature : Molecular simulations compared to experiments,

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CO2 adsorption in alkali cations exchanged Y Faujasites : a Quantum chemical study compared to experiments

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Coadsorption of CO2, CH4 and their binary mixture in NaY: a combination of molecular simulation with gravimetry-manometry measurements and microcalorimetry

International audienceThe adsorption of pure carbon dioxide and methane, and their equimolar mixture were explored in a model zeolite NaY by combining grand canonical Monte Carlo simulations and an original experimental approach based on gravimetry/manometry and manometry/microcalorimetry devices. Both experimental and calculated adsorption isotherms and enthalpy profiles obtained for the single gas and a 50/50 binary mixture are provided for pressures up to 30 bar. The gravimetry/manometry apparatus allows the determination of single gas and mixture isotherms whereas the manometry/microcalorimetry system allows a direct access to the enthalpies of adsorption enabling also a validation of the computational work. The aim here is to fully characterize the interactions of the gas mixture in NaY which are thus compared to those for the single gas adsorption. In this way, the computational studies allow an understanding of the complex adsorption phenomena in play. These calculations which are based on different interatomic potentials available in the literature to describe the adsorbate/adsorbent and adsorbate/adsorbate interactions, consist first of selecting the most convenient set of potential parameters able to reproduce well the adsorption data for the pure components. These reliable force fields are thus transferred to the study of the equimolar CO2/CH4 gas mixture. In agreement with the experiments, our simulations show a high selectivity of CO2 over CH4 in NaY for the whole range of pressure. We then report a complete exploration of the preferential adsorption sites for both adsorbates in the gas mixture which are compared to that observed for the pure component adsorption. The originality and the strength of this paper is thus to combine novel experimental tools and realistic models to provide a detailed picture of the microscopic adsorption and co-adsorption mechanisms in NaY

Adsorption of carbon dioxide in SAPO STA-7 and AlPO-18: Grand Canonical Monte Carlo simulations and Microcalorimetry measurements, I. Déroche, L. Gaberova, G. Maurin, P. Llewellyn, M. Castro & P. Wright

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Influence of the silicon content and chemical disorder of the framework on the CO2 adsorption properties of SAPO STA-7: Grand Canonical Monte Carlo simulations combined to Microcalorimetry measurements

The adsorption properties of carbon dioxide in SAPO STA-7 material have been investigated by combining grand canonical Monte Carlo simulations and microcalorimetry measurements. The computational studies, based on newly derived interatomic potentials to describe the adsorbate/adsorbent interactions, provide both adsorption isotherms and enthalpy profiles as a function of coverage for AlPO4-18 and SAPO STA-7 characterized by two different silicon contents. It is shown that both the silicon content and the microscopic description of the SAPO framework characterized by a chemical disorder created by the introduction of Si atoms significantly modify the CO, adsorption behavior of the material. The originality and the strength of this article is that it combines experimental tools and realistic models to provide a detailed picture of the microscopic adsorption mechanism for each type of zeolite material.</p

Vanadium-containing SBA-15 systems prepared by direct synthesis: physico-chemical and catalytic properties in the decomposition of dichloromethane

59-4 FIELD Section Title:Air Pollution and Industrial Hygiene 49, 66, 67 Department of Materials Science and Chemical Engineering, Politecnico di Torino, Turin, Italy. FIELD URL: written in EnglishVx/SBA-15 catalysts (V content = 0.7-4.8 wt.%) were directly synthesized and tested for the oxidative decompn. of dichloromethane; impregnation-synthesized SBA-15 and V/SBA-15 catalysts were ref. samples. Catalyst structural and surface properties were characterized by complementary physicochem. techniques. Vx/SBA-15 materials with isolated V sites were catalytically active for dichloromethane decompn.; max. conversion was obtained by a catalyst with 2.2 wt.% V. In Vx/SBA-15 catalysts prepd. by direct synthesis, V occurred mainly as isolated sites with tetrahedral coordination; its content did not reach the theor. monolayer capacity (~4 wt.%). Unlike impregnation-synthesized catalysts, oligomeric VOx species formed only at high V content. [on SciFinder(R)

Evaluation of STA-7 and AlPO18 for the adsorption of CH4 and CO2: microcalorimetry, neutron scattering and molecular simulation

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