Search

Your search keyword '"Tronconi, E."' showing total 276 results
Start Over Author "Tronconi, E."
276 results on '"Tronconi, E."'

14. Kinetic Modeling of Dynamic Aspects of the Standard NH3-SCR Reaction Over V2O5-WO3/TiO2 and Fe-Zeolite Commercial Catalysts for the Aftertreatment of Diesel Engines Exhausts Modélisation cinétique d’aspects dynamiques de la réaction de RCS-NH3 standard sur des catalyseurs commerciaux V2O5-WO3/TiO2 et Fe-zéolite pour le post-traitement de gaz d’échappement de moteurs Diesel

Author

Nova I., Colombo M., and Tronconi E.

Subjects
Chemical technology, TP1-1185, Energy industries. Energy policy. Fuel trade, HD9502-9502.5
Abstract

Dynamic kinetic data collected over commercial V2O5-WO3/TiO2 and Fe-zeolite catalysts analyzing the standard NH3-SCR of NO for the abatement of NOx from vehicle exhausts showed transient effects at low temperatures related to the inhibiting action of excess ammonia. In order to describe such transient effects, a specific rate expression accounting for NH3 inhibition of the standard SCR reaction is needed in mathematical models of real SCR converters. We present herein a dual-site Mars-Ven Krevelen-type rate equation suitable to describe dynamic features associated with ammonia injection and shut-off over both V-based and Fe-zeolite catalysts. Les données cinétiques dynamiques recueillies sur des catalyseurs V2O5-WO3/TiO2 et Fe-zéolite commerciaux en analysant le RCS-NH3 standard du NO pour la réduction des NOx des gaz d’échappement de véhicules ont montré des effets transitoires à basse température, liés à l’action inhibitrice d’ammoniac en excès. Afin de décrire de tels effets transitoires, une expression de la vitesse spécifique prenant en compte l’inhibition par NH3 de la réaction de RCS standard est nécessaire pour des modèles mathématiques de convertisseurs par RCS réels. Nous présentons ici une équation de vitesse de type Mars-Van Krevelen à double site pour décrire les caractéristiques dynamiques associées à l’injection et à l’arrêt de l’ammoniac sur des catalyseurs à la fois à base de V et Fe-zéolite.

Published
2011
Full Text
View/download PDF

25. FT-IR and TPD investigation of the NO (sub)x storage properties of BaO/Al (sub)2 O (sub)3 and Pt-BaO/Al (sub)2 O (sub)3 catalysts

Author

Prinetto, F., Ghiotti, G., Nova, I., Lietti, L., Tronconi, E., and Forzatti, P.

Subjects
Chemistry, Physical and theoretical -- Research, Catalysts -- Physiological aspects, Aluminum -- Physiological aspects, Oxygen -- Physiological aspects, Platinum -- Physiological aspects, Barium -- Physiological aspects, Chemicals, plastics and rubber industries
Published
2001

43. Design of Pt-Sn catalysts on mesoporous titania films for microreactor application

Author

Ismagilov, Z.R., Matus, E.V., Yakutova, A., Protasova, L.N., Ismagilov, I.Z., Kerzhentsev, M.A., Rebrov, E.V., Schouten, J.C., Tronconi, E., Micro Flow Chemistry and Synthetic Meth., and Chemical Reactor Engineering

Subjects
Materials science, Adsorption, Chemical engineering, Inorganic chemistry, Nanoparticle, General Chemistry, Thin film, Heterogeneous catalysis, Mesoporous material, Bimetallic strip, Catalysis, Titanium oxide
Abstract

A new generation of nanostructured Pt–Sn/TiO 2 catalytic thin films has been developed by deposition of Pt–Sn mixed-metal precursors from organic solvents on mesoporous TiO 2 /Ti films with a thickness of 200–300 nm. The titania sol was obtained by templating a TiO 2 precursor with Pluronic F127 surfactant. The films were prepared on Ti substrates by spin-coating. The influence of the F127/Ti ratio in the range between 0.006 and 0.050, the pH of the titania sol between 1.5 and 2.0, and the aging time between 8 and 240 h on the morphology and porous structure of titania films was investigated. A TiO 2 film with the highest degree of the long-order structure was obtained at a surfactant/Ti molar ratio of 0.009, a pH of 1.5, and an aging time of 24 h. This film has a hexagonal pore structure with a mean pore size of 3.5 nm and a porosity of 25%. A powder titania support with a similar chemical composition and morphology was also produced and used for optimization of an active component deposition. The Pt–Sn carbonyl [Pt 3 (CO) 3 (SnCl 3 ) 2 (SnCl 2 ·H 2 O)] n −2 n clusters were synthesized separately from monometallic precursors. They were loaded onto the TiO 2 supports by impregnation or adsorption. The adsorption of the Pt–Sn precursor for 24 h from an ethanol solution with concentrations of Pt and Sn of 2.0 and 1.2 mg/ml, respectively, followed by a vacuum treatment at 463 K, resulted in Pt–Sn nanoparticles embedded in the mesoporous titania network. An average size of bimetallic nanoparticles was 1.5–2 nm with a narrow particle size distribution. A reaction rate in terms of TOF between 0.2 and 3.3 min −1 was observed in the hydrogenation of citral over the Pt–Sn/TiO 2 catalysts. The selectivity to the unsaturated alcohols was as high as 90% at a citral conversion above 95%.

Published
2009
Full Text
View/download PDF

48. Mechanistic Study of the NO + NH4NO3 Reaction on H- and Fe/H-BEA Zeolites Using 15N and 18O Labeled Species.

Author

Tronconi, E., Nova, I., Nováková, J., Bernauer, M., Sazama, P., and Sobalík, Z.

Subjects
ZEOLITES, AMMONIUM nitrate, CATALYTIC reduction, DIESEL motor exhaust gas, NITROUS oxide
Abstract

Reduction of NO by NH3 over metal-promoted zeolites represents the principal reaction in the selective catalytic reduction (SCR) technology for NOx removal from Diesel engine exhausts. It has been established that addition of ammonium nitrate (AN) to the reaction mixture substantially enhances the rate of this reaction, decreasing the temperature necessary for an efficient deNOx process. Nevertheless, the nature of this effect has not been completely elucidated. To investigate the NO + AN reaction mechanism, we have used individual reactants labeled with either 15N or 18O (or both isotopes), thus obtaining an experimental background for proposing the route of the SCR accelerated by AN addition. For this study, we have used as the catalysts H-BEA and Fe/H-BEA zeolites with various Si/Al ratios and various amounts and states of the iron species. [ABSTRACT FROM AUTHOR]

Published
2018
Full Text
View/download PDF

50. Effect of the NH4NO3Addition on the Low-T NH3-SCR Performances of Individual and Combined Fe- and Cu-Zeolite Catalysts

Author

Villamaina, R., Nova, I., Tronconi, E., Maunula, T., and Keenan, M.

Abstract

We have measured NOx conversions and N2O productions over Fe-BEA and Cu-SAPO catalysts and over their sequential arrangements under Enhanced SCR conditions, resulting from the addition of an aqueous solution of ammonium nitrate (AN) to the typical Standard SCR feed stream, and we have compared them to those observed under Standard and Fast SCR conditions. The expected strong enhancement of the poor low temperature activity of the Fe-BEA catalyst was confirmed: both NH3and NOx conversions and N2O formations similar to those of the Fast SCR reaction were achieved when cofeeding ammonium nitrate. On the other hand, the Cu-SAPO efficiency was drastically decreased by the addition of AN at low temperatures, possibly due to trapping of the ammonium nitrate salt within the SAPO zeolite, characterized by smaller pores than those of the BEA zeolite. The Cu-SAPO performances were recovered only at T > 250 °C with a huge release of N2O due to the thermal decomposition of AN. The combined system with the Fe-zeolite sample placed upstream of the Cu-zeolite also exhibited outstanding low temperature deNOx performances, with even lower N2O production than over the Fe-zeolite only at the same Enhanced SCR (E-SCR) conditions.

Published
2019
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results