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Structural characterization and catalytic evaluation of supported copper – ceria catalysts for soot oxidation / Komateedi N. Rao in Industrial & engineering chemistry research, Vol. 50 N° 21 (Novembre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11960–11969 Titre : Structural characterization and catalytic evaluation of supported copper – ceria catalysts for soot oxidation Type de document : texte imprimé Auteurs : Komateedi N. Rao, Auteur ; P. Venkataswamy, Auteur ; Benjaram M. Reddy, Auteur Année de publication : 2011 Article en page(s) : pp. 11960–11969 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Soot  oxidation  catalyst Résumé : The present investigation was undertaken with the aim of designing a noble-metal-free diesel soot oxidation catalyst that can work at relatively low temperatures. Accordingly, a series CeO2–Al2O3, CeO2–ZrO2, and CeO2–SiO2 mixed-oxide-supported copper catalysts were prepared by a modified deposition–precipitation method from ultradilute aqueous solutions and evaluated for soot oxidation at normal atmospheric pressure. The structural and electronic properties were investigated by various physicochemical techniques, namely, X-ray diffraction (XRD), Raman spectroscopy, temperature-programmed desorption (TPD), temperature-programmed reduction–oxidation (TPR–TPO), temperature-programmed mass spectroscopy (TP-MS), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Formation of a Ce1–xCuxO2 solid solution was inferred from XRD, TPR, and Raman spectroscopy studies. The TEM results revealed the presence of copper–ceria nano-oxides of 5–7-nm size in highly dispersed form. The TPR–TPO results suggested a profound influence of mixed-oxide supports on the reduction behavior of copper oxide. In particular, the TP-MS results provided direct evidence for labile oxygen generation. Among the investigated catalysts, the CuO/CeO2–ZrO2 combination exhibited excellent catalytic activity for soot oxidation, with T1/2 = 611 K. Incorporation of Cu2+ into the ceria–zirconia solid solution favored the creation of more structural defects, which accelerate the oxygen diffusion and induce more of the surface-active oxygen species that are responsible for the enhanced soot oxidation activity at lower temperatures. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201474p [article] Structural characterization and catalytic evaluation of supported copper – ceria catalysts for soot oxidation [texte imprimé] / Komateedi N. Rao, Auteur ; P. Venkataswamy, Auteur ; Benjaram M. Reddy, Auteur . - 2011 . - pp. 11960–11969. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11960–11969 Mots-clés : Soot  oxidation  catalyst Résumé : The present investigation was undertaken with the aim of designing a noble-metal-free diesel soot oxidation catalyst that can work at relatively low temperatures. Accordingly, a series CeO2–Al2O3, CeO2–ZrO2, and CeO2–SiO2 mixed-oxide-supported copper catalysts were prepared by a modified deposition–precipitation method from ultradilute aqueous solutions and evaluated for soot oxidation at normal atmospheric pressure. The structural and electronic properties were investigated by various physicochemical techniques, namely, X-ray diffraction (XRD), Raman spectroscopy, temperature-programmed desorption (TPD), temperature-programmed reduction–oxidation (TPR–TPO), temperature-programmed mass spectroscopy (TP-MS), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Formation of a Ce1–xCuxO2 solid solution was inferred from XRD, TPR, and Raman spectroscopy studies. The TEM results revealed the presence of copper–ceria nano-oxides of 5–7-nm size in highly dispersed form. The TPR–TPO results suggested a profound influence of mixed-oxide supports on the reduction behavior of copper oxide. In particular, the TP-MS results provided direct evidence for labile oxygen generation. Among the investigated catalysts, the CuO/CeO2–ZrO2 combination exhibited excellent catalytic activity for soot oxidation, with T1/2 = 611 K. Incorporation of Cu2+ into the ceria–zirconia solid solution favored the creation of more structural defects, which accelerate the oxygen diffusion and induce more of the surface-active oxygen species that are responsible for the enhanced soot oxidation activity at lower temperatures. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201474p