Data di Pubblicazione:
2011
Abstract:
In this paper the results obtained in our previous studies on the reduction of nitrates by CO over
Pt–K/Al2O3 and Pt–Ba/Al2O3 catalysts are compared and discussed in order to define the chemistry that
leads to nitrogen evolution during the regeneration of the different lean NOx traps. The reaction mechanisms
and pathways leading to N2 formation under dry conditions are investigated by complementary
transient dynamic experiments and FT-IR analyses.
In both cases, the reduction of stored NOx by CO occurs according to a Pt catalyzed surface pathway that
does not involve the release of NOx in the gas phase as a first step, is effective already at low temperature
and leads to nitrogen. The proposed reaction scheme implies the formation of surface isocyanate species
followed by their reaction with residual stored NOx to give nitrogen. This is the exclusive route for nitrogen
formation.
Tipologia CRIS:
03A-Articolo su Rivista
Keywords:
Lean NOx traps
Pt–K/Al2O3
Pt–Ba/Al2O3
Reduction by CO
Transient response methods
FT-IR spectroscopy
Elenco autori:
S. Morandi; G. Ghiotti; L. Castoldi; L. Lietti; I. Nova; P. Forzatti
Link alla scheda completa:
Pubblicato in: