Rivallan, Mickaël, et al. "Insights into the mechanisms of isopropanol conversion on gamma-Al2O3 by dielectric barrier discharge." Plasma Processes and Polymers (2012).
Abstract: Mechanisms of isopropanol conversion on gamma-Al2O3 by dielectric barrier discharge plasma are elucidated by the means of operando Fourier Transformed InfraRed spectroscopy. In that case, it is shown that the isopropanol conversion proceeds by successive steps. Firstly, via the oxidation of isopropanol into acetone by atomic oxygen and ozone produced in the plasma composed of dry air. Secondly, after aldolization of acetone into mesityl oxide at the surface of the gamma-Al2O3 catalyst. Thirdly, after fragmentation of mesityl oxide into acetaldehyde and isobutene. Such cascade reactions are only possible when a catalyst is placed in the discharge zone (in-plasma catalysis). It initially supports the isopropanol molecules and then allows products condensation before their fragmentation.
Keywords: DBD, isopropanol, FTIR, plasma, catalysis
Theme: PCI
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Leyva, C., et al. "Activity and surface properties of NiMo/SiO2-Al2O3 catalysts for hydroprocessing of heavy oils." Applied Catalysis A: General. 425-426 (2012): 1–12.
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R. Moraes, K. Thomas, S. Thomas, S. Van Donk, G. Grasso, J-P. Gilson, M. Houalla. "Ring opening of decalin and methylcyclohexane over bifunctional Ir/WO3/Al2O3 catalysts." Journal of Catalysis. Submitted (2012).
Abstract: Ring opening reactions of decalin and methylcyclohexane (MCH) over bifunctional catalysts (1.2Ir/WO3/Al2O3) were investigated. A series of catalysts containing up to 5.3 at. W/nm2 and 1.2 wt% Ir, was prepared. The acidity of the solids was monitored by low-temperature CO adsorption followed by infrared spectroscopy. Characterization of the Ir metal phase was performed by H2 chemisorption and x-ray diffraction. The activity and product selectivity patterns obtained for the decalin ring opening reaction, were compared with those observed for methylcyclohexane (MCH). For both naphthenes, ring contraction precedes ring opening, suggesting a similar ring opening mechanism. Kinetic modeling based on the proposed reaction network allowed the determination of the activation energies and initial rates. Based on the yields and products distribution obtained for
Keywords: Alumina, tungsten, iridium, bifunctional catalysts, decalin, methylcyclohexane, ring-opening
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E. Le Guludec, L. Oliviero, J-P Gilson, F. Maugé, M. Rebeilleau, V. De Grandi, S. van Donk. "From gas to liquid phase sulfidation – An IR spectroscopy study." Catalysis Letters. Accepted (2012).
Abstract: A side by side characterization of gas and liquid phase activation of a CoMo/Al2O3 hydrodesulfurization (HDS) catalyst is reported using thiophene hydrodesulfurization as a test reaction and CO adsorption monitored by infrared spectroscopy. The liquid phase sulfidation (high pressure, dimethyldisulfide) leads to the formation of CoMoS sites with higher intrinsic activity compared to the gas phase (H2S/H2).
Keywords: hydrotreatment, sulfide catalyst structure, liquid phase sulfidation, effect of carbon, carbon monoxide adsorption, thiophene HDS
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Zanzottera, Cristina, et al. "Physico-Chemical Properties of Imogolite Nanotubes Functionalized on Both External and Internal Surfaces." The Journal of Physical Chemistry C. Accepted (8.03.2012) (2012).
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Volkringer, C., et al. "Infrared Spectroscopy Investigation of the Acid Sites in the Metal-Organic Framework Aluminum Trimesate MIL-100(Al)." J. Phys. Chem. C (2012): 120203141819008.
Abstract: Infrared spectra of MIL-100(Al) have been recorded after evacuation from room temperature up to 623 K. In addition to adsorbed water molecules characterized by specific (ν+δ)H2O combination bands at about 5300 cm-1, spectra analysis shows the presence of impurities like carboxylic acid and nitrates resulting from the synthesis step, explaining the low amount of Al-OH groups detected. The Lewis acidity has been characterized by CO [ν(CO) at 2183 cm-1], pyridine [ν8a band estimated at 1618 cm-1] and CD3CN [ν(CN) of at 2326 cm-1] adsorption on the activated sample. It is strongas revealed by the ν(CN) wavenumber. Interestingly, CO gives rise to an interaction weaker than that expected from pyridine and CD3CN results. Quantitative results relative to the number of Al3+5c sites are in full agreement with those reported elsewhere from 27Al NMR experiments. The Brønsted acidity mainly results from the presence of coordinated water species in the non-fully dehydrated sample and not from the structural Al-OH groups.
Theme: PCI
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Seo, Y. - K., et al. "Energy-Efficient Dehumidification over Hierachically Porous Metal-Organic Frameworks as Advanced Water Adsorbents." Adv. Mater.. 24.6 (2012): 806–810.
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Yang, Q., et al. "Probing the adsorption performance of the hybrid porous MIL-68(Al): a synergic combination of experimental and modelling tools." J. Mater. Chem. (2012).
Abstract: A joint experimental/modelling approach has been conducted to get some insight into the microscopic mechanism in play for a series of small gas molecules including CH4, CO2, N2 and H2S in the porous aluminium-based (Al3+) terephthalate MIL-68 solid containing two distinct pore channels (MIL: Materials of Institute Lavoisier). A further step consisted of predicting the separation performances of this material for the CO2/CH4 and CO2/N2 mixtures that are compared to the other MOFs reported so far in the literature. The theoretical impact of the functionalization of the organic linker via amino groups on the selectivity of this hybrid material for these gas mixtures is then pointed out. Finally, the stability of the solid upon H2S adsorption which is commonly present in the raw natural gas is confirmed.
Theme: EDD
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Wiersum, A. D., et al. "An Evaluation of UiO-66 for Gas-Based Applications." Chem. Asian J.. 6.12 (2011): 3270–3280.
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Meunier, F. C. "Comments on “Surface interfaces in low temperature water-gas shift: The metal oxide synergy, the assistance of co-adsorbed water, and alkali doping” by Jacobs and Davis, Int J Hydrogen Energy, 35 (2010) 3522-36." International Journal of Hydrogen Energy (2011). 17 May. 2012 <http://dx.doi.org/10.1016/j.ijhydene.2011.11.053>.
Abstract: In a recent account, Jacobs and Davis discussed in some detail
the reaction mechanism of the low-temperature water-gas
shift (WGS) reaction over metal-promoted oxide catalysts and
supported surface formates as being the main reaction intermediates
[1]. The WGS reaction is crucial for the production of
CO-free H2 [2-6]. A series of statements in the last paragraph
of Section 6 (p. 3531-32) of this account [1] directly referred to
some published work of mine [7]. These statements appear to
be ambiguous, if not misleading, and therefore I would like to
clarify the related facts.
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M. Moothanchery, I. Naydenova, S. Mintova, V. Toal. "Nanozeolites doped photopolymer layers with reduced shrinkage." Optics Express. 19.25 (2011): 25786–25791.
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Eng-Poh Ng, Daniel Chateigner, Thomas Bein, Valentin Valtchev, Svetlana Mintova. "Capturing Ultrasmall EMT Zeolite from Template-Free Systems." Science (2011).
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V. Valtchev, E. Balanzat, V. Mavrodinova, I. Diaz, J.El Fallah, J.-M. Goupil. "High Energy Ion Irradiation Induced Ordered Macropores in Zeolite Crystals." J. Am. Chem. Soc.. 133.46 (2011): 18950–18956.
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L. Dimitrov, V. Valtchev, D. Nihtianova, Y. Kalvachev. "Submicrometer zeolite A crystals formation: low-temperature crystallization versus vapor phase gel transformation." Crystal Growth & Design. 11 (2011): 4958–4962.
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B. Louis, A. Vicent, C. Fernandez, V. Valtchev. "Acid Sites Relationship Study of Nano- and Micrometer-Sized Zeolite Crystal." J. Phys. Chem. C. 115 (2011): 18603–18610.
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