Journal ArticleDOI
Redox behaviour of transition metal ions in zeolites. Part 3.—Auto-reduction of cupric ions in Y zeolites
Reads0
Chats0
TLDR
In this article, it was shown that at temperatures above 650 K cupric ions are reduced to some extent to cuprous ions, and that Lewis sites are also formed upon degassing.Abstract:
In CuY zeolites degassed at temperatures above 650 K cupric ions are reduced to some extent to cuprous ions.Evidence for this process of auto-reduction was taken from the decrease in weight of the sample, and the detection of a desorbing gas in a volumetric system. The latter was identified as oxygen. U.v. reflectance spectroscopy showed directly the decrease of the Cu2+ species upon outgassing and their increase after oxygen adsorption. Excitation spectra showed the presence of Cu+ ions after high temperature degassing. Infrared spectroscopic techniques showed that Lewis sites are also formed upon degassing. A mechanism is proposed that accounts for the observations.read more
Citations
More filters
Journal ArticleDOI
Catalytic removal of NO
TL;DR: In this paper, the authors review the catalytic reactions for the removal of NO and discuss the reduction of NO in the presence of NH3, CO, H-2 or hydrocarbons as well as the decomposition of NO.
Book ChapterDOI
Characterization of oxide surfaces and zeolites by carbon monoxide as an IR probe molecule
TL;DR: In this article, a review of the data characterizing CO adsorption on surface cationic sites of oxides including supported materials and microporous and mesoporous materials is presented.
Journal ArticleDOI
Nature of active species in copper-based catalysts and their chemistry of transformation of nitrogen oxides
TL;DR: Copper-based catalysts are active in a wide range reactions of transformation of nitrogen oxides and represent an useful model system to better understand the fundamental aspects of the chemistry and mechanism of reaction of catalytic transformation of these pollutants.
Journal ArticleDOI
Surface and bulk properties of Cu–ZSM-5 and Cu/Al2O3 solids during redox treatments. Correlation with the selective reduction of nitric oxide by hydrocarbons
TL;DR: In this article, the redox properties of Cu ions implanted in ZSM-5 and supported on Al2O3, catalysts active in the selective reduction of NO by hydrocarbons such as propane, are investigated.
Journal ArticleDOI
The interaction of NO with copper ions in ZSM5 : an EPR and IR investigation
Elio Giamello,Damien Martin Murphy,Giuliana Magnacca,Claudio Morterra,Y. Shioya,T. Nomura,Masakazu Anpo +6 more
TL;DR: In this paper, the interaction of nitric oxide with copper ZSM5 zeolites at room temperature has been studied by EPR and FT-IR spectroscopy in the aim of investigating the surface intermediates involved in the decomposition of NO to N2 and O2.
Related Papers (5)
Redox chemistry in excessively ion-exchanged Cu/Na-ZSM-5
Evidence for the nature of true Lewis sites in faujasite-type zeolites
Peter A. Jacobs,Hermann K. Beyer +1 more