Journal ArticleDOI
Spectroscopic studies of surface copper spinels. Influence of pretreatments on chemical state of copper
A. Sepúlveda,C. Márquez,Inmaculada Rodríguez-Ramos,Antonio Guerrero-Ruiz,José Luis García Fierro +4 more
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TLDR
In this paper, the nature of copper species of a series of alumina-supported copper samples was investigated by the kinetics of reduction, x-ray photoelectron spectroscopy, temperature-programmed desorption-mass spectrometry of chemisorbed NO and infrared spectroscopic analysis of CO and CO probes.Abstract:
The nature of copper species of a series of alumina-supported copper samples was investigated by the kinetics of reduction, x-ray photoelectron spectroscopy, temperature-programmed desorption-mass spectrometry of chemisorbed NO and infrared spectroscopy of chemisorbed NO and CO probes. The role of these copper species was also examined in the catalytic decomposition of NO. The surface properties of copper were found to depend strongly on both Cu loading and calcination treatmentread more
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Spectroscopic Study of a Cu/CeO2Catalyst Subjected to Redox Treatments in Carbon Monoxide and Oxygen☆
TL;DR: In this article, the authors investigated the effect of the interaction of a calcined Cu/CeO{sub 2} catalyst with CO and reoxidation with O(sub 2 ) using CO-TPR, EPR, FTIR of adsorbed CO and XPS.
Journal ArticleDOI
Partial oxidation of methanol to produce hydrogen over CuZn-based catalysts
TL;DR: In this paper, the authors studied the effect of the copper surface area on the catalytic performance of methanol and showed that the performance of the CuZnO and ZnO/Al2O3 catalysts is directly related to the surface area.
Journal ArticleDOI
Nature of Copper Active Sites in the Carbon Monoxide Oxidation on CuAl2O4and CuCr2O4Spinel Type Catalysts
TL;DR: In this article, the authors used ammonium carbonate and nitric acid washing solutions to extract uncombined copper oxide and showed that ammonium-carbonate was only effective for removing dispersed CuO, whereas nitric acids removed both dispersed and crystalline CuO. The results indicated that the active sites are copper species derived from CuAl2O4 and CuCr2O 4 spinels rather than from CuO and indicated that Cu species in tetrahedral coordination lead to higher activity.
Journal ArticleDOI
Oxidative Methanol Reforming Reactions on CuZnAl Catalysts Derived from Hydrotalcite-like Precursors
S. Murcia-Mascarós,Rufino M. Navarro,Luisa Ma. Gómez-Sainero,Umberto Costantino,Morena Nocchetti,José Luis García Fierro +5 more
TL;DR: In this article, X-ray diffraction was used to identify the crystalline phases of the precursors and of the air-calcined CZA catalysts used in both partial oxidation and oxyreforming reactions of methanol.
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TPR and XRD studies of yttria-doped ceria/γ-alumina-supported copper oxide catalyst
TL;DR: In this paper, temperature-programmed reduction (TPR) and X-ray diffraction (XRD) were used to characterize the catalysts of CuO/γ-Al2O3 catalysts.
References
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Journal ArticleDOI
Catalytic Aluminas: Surface Models and Characterization of Surface Sites
Helmut Knözinger,Paul Ratnasamy +1 more
TL;DR: Aluminas have been used extensively as adsorbenu and active catalysrs and catalyst supponsm the pas as discussed by the authors, and they are used as catalysts for the larter process LS also caralyzed by molybdena-alumina.
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Initial and final state effects in the ESCA spectra of cadmium and silver oxides
TL;DR: In this article, the effects of extra-atomic relaxation on chemical shifts were examined in order to elucidate the cause of the anomalous chemical shifts for Cd and Ag oxides.
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Copper(II) ion-exchanged ZSM-5 zeolites as highly active catalysts for direct and continuous decomposition of nitrogen monoxide
Masakazu Iwamoto,Hiroshi Furukawa,Yoshihiro Mine,Fumihide Uemura,Shin-ichi Mikuriya,Shuichi Kagawa +5 more
TL;DR: In this article, ZSM-5 zeolites containing Cu2+ ions showed unusually high and steady state activity for the catalytic decomposition of nitrogen monoxide; for example, the degrees of conversions of NO, and of conversion into N2 and O2 were 97, 85, and 70%, respectively, at 823 K with a contact time of 10.0 g s cm−3 over 73% exchanged Cu-ZSM−5.
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Surface spectroscopic characterization of Cu/Al2O3 catalysts
Brian R. Strohmeier,Brian R. Strohmeier,Donald E. Levden,Donald E. Levden,R.Scott Field,R.Scott Field,David M. Hercules,David M. Hercules +7 more
TL;DR: In this article, the surface properties of impregnated CuAl2O3 catalysts were investigated by a variety of spectroscopic techniques: X-ray photoelectron spectroscopy (ESCA or XPS), low-energy ion scattering spectro-graphs (ISS), photoacoustic spectroscope (PAS), and Xray diffraction.
Journal ArticleDOI
Catalytic decomposition of nitric oxide over Cu-zeolites
Yuejin Li,W.Keith Hall +1 more
TL;DR: In this article, the authors investigated the performance of Cu-exchanged zeolites as catalysts for NO decomposition, and found that the NO decomposition rate was first order in NO pressure and was inhibited by O2.