INCAPE   05401
INSTITUTO DE INVESTIGACIONES EN CATALISIS Y PETROQUIMICA "ING. JOSE MIGUEL PARERA"
Unidad Ejecutora - UE
artículos
Título:
Diesel soot and NOx abatement: K/La2O3 catalyst stability
Autor/es:
M.A. PERALTA; M. A, ULLA; C.A. QUERINI
Revista:
APPLIED CATALYSIS B-ENVIRONMENTAL
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Año: 2010 vol. 101 p. 38 - 44
ISSN:
0926-3373
Resumen:
Soot particles and nitrogen oxides are the main
pollutants emitted by a diesel engine. In this work, the activity and the
stability of the KOH/La2O3 catalyst are studied. This catalyst is able to
adsorb NOx, which is a good property for the catalyst in order to be used as
aNOx trap. In addition, it is active for soot combustion as determined by
temperature-programmed oxidation analyses. FTIR, XRD, CO2-TPD, Pulses of CO2,
and BET techniques are used in order to characterize the catalysts. The
catalytic surface composition depends upon the relative partial pressures of H2O,
CO2, NO and O2. Despite the different surface compositions, the catalytic
activity remains quite stable, under operation conditions similar to those of a
real diesel exhaust. High temperature treatments, such as 800 ◦C, and especially in
the presence of water, leads to an irreversible catalyst deactivation due to
potassium volatilization. The water condensed on the catalyst, could wash-out a
fraction of the potassium from the outer surface, leading to a decrease in
activity. However, when the catalyst is treated at 400 ◦C, potassium diffuses
from inside the pores to the external surface, thus recovering activity for soot combustion.