Documents disponibles écrits par cet auteur

Hydrodechlorination of light organochlorinated compounds and their mixtures over Pd/TiO2-washcoated minimonoliths / Michael Bartoszek in Industrial & engineering chemistry research, Vol. 48 N° 6 (Mars 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 6 (Mars 2009) . - pp. 2826–2835 Titre : Hydrodechlorination of light organochlorinated compounds and their mixtures over Pd/TiO2-washcoated minimonoliths Type de document : texte imprimé Auteurs : Michael Bartoszek, Auteur ; Andreas Martin, Auteur Année de publication : 2009 Article en page(s) : pp. 2826–2835 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Catalytic  hydrodechlorination  Dichloromethane  Tetrachloroethylene  Chloroform  Pd/TiO2-washcoated  cordierite  minimonoliths Résumé : The gas-phase catalytic hydrodechlorination (CHD) of dichloromethane (DCM), tetrachloroethylene (TTCE), and chloroform (CF) and their mixtures was studied over Pd/TiO2-washcoated cordierite minimonoliths. Experiments were carried out in a flow reactor at 120−300 °C, 1 bar, and 0.45 g min/mL. Catalytic runs with the pure compounds at 200 °C led to 60−100% conversion following the sequence CF > TTCE > DCM. Catalyst deactivation and regeneration were also examined. Lower conversions (between 30% and 95%) and catalyst deactivation were observed when mixtures of organochlorinated compounds where fed as reactants. DCM was the most affected when binary and ternary mixtures were used. Catalyst samples were characterized before and after reaction by various temperature-programmed studies (H2 TPR, He TPD, NH3 TPD, and TPO), H2 chemisorption, and XPS measurements. Most characterization studies were carried out using an online coupled mass spectrometer, thus allowing the parallel detection of different fragments and species corresponding to several hydrocarbons and HCl. In some experiments, a fast GC−ToF−MS system was used. The catalytic activity of spent samples was partially recovered by heating them in flowing air and then in 5% H2/N2. However, the initial reaction rate decreased by 62% over samples used in three consecutive runs when ternary mixtures were fed. Carbonaceous deposits of different nature and changes in the oxidation state of Pd (Pd0 to Pd2+ and Pd4+) appear to play key roles in catalyst deactivation, whereas acidity was found to remain almost the same for fresh and used catalyst samples. Carbonaceous deposits were removed by heating at temperatures lower than 400 °C in flowing air. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8013742 [article] Hydrodechlorination of light organochlorinated compounds and their mixtures over Pd/TiO2-washcoated minimonoliths [texte imprimé] / Michael Bartoszek, Auteur ; Andreas Martin, Auteur . - 2009 . - pp. 2826–2835. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 6 (Mars 2009) . - pp. 2826–2835 Mots-clés : Catalytic  hydrodechlorination  Dichloromethane  Tetrachloroethylene  Chloroform  Pd/TiO2-washcoated  cordierite  minimonoliths Résumé : The gas-phase catalytic hydrodechlorination (CHD) of dichloromethane (DCM), tetrachloroethylene (TTCE), and chloroform (CF) and their mixtures was studied over Pd/TiO2-washcoated cordierite minimonoliths. Experiments were carried out in a flow reactor at 120−300 °C, 1 bar, and 0.45 g min/mL. Catalytic runs with the pure compounds at 200 °C led to 60−100% conversion following the sequence CF > TTCE > DCM. Catalyst deactivation and regeneration were also examined. Lower conversions (between 30% and 95%) and catalyst deactivation were observed when mixtures of organochlorinated compounds where fed as reactants. DCM was the most affected when binary and ternary mixtures were used. Catalyst samples were characterized before and after reaction by various temperature-programmed studies (H2 TPR, He TPD, NH3 TPD, and TPO), H2 chemisorption, and XPS measurements. Most characterization studies were carried out using an online coupled mass spectrometer, thus allowing the parallel detection of different fragments and species corresponding to several hydrocarbons and HCl. In some experiments, a fast GC−ToF−MS system was used. The catalytic activity of spent samples was partially recovered by heating them in flowing air and then in 5% H2/N2. However, the initial reaction rate decreased by 62% over samples used in three consecutive runs when ternary mixtures were fed. Carbonaceous deposits of different nature and changes in the oxidation state of Pd (Pd0 to Pd2+ and Pd4+) appear to play key roles in catalyst deactivation, whereas acidity was found to remain almost the same for fresh and used catalyst samples. Carbonaceous deposits were removed by heating at temperatures lower than 400 °C in flowing air. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8013742