Dynamics of the SCR-DeNO{sub x} reaction by the transient-response method
- Politecnico di Milano (Italy). Dipt. di Chimica Industriale e Ingegneria Chimica
The unsteady-state kinetics of NH{sub 3} adsorption-desorption and of selective catalytic reduction (SCR) of NO with NH{sub 3} were studied over model V{sub 2}O{sub 5}/TiO{sub 2} and V{sub 2}O{sub 5}-WO{sub 3}/TiO{sub 2} catalysts by transient response techniques. Over both catalysts the dynamic experiments could be successfully described by a kinetic model assuming (1) negligible NO adsorption on the catalyst surface; (2) nonactivated NH{sub 3} adsorption; (3) a Temkin-type NH{sub 3} coverage dependence of the desorption energy; (4) a nonlinear dependence of the SCR reaction rate on the NH{sub 3} surface coverage. Thus, the results are supportive of an Eley-Rideal mechanism for the SCR reaction and of a significant heterogeneity for adsorption-desorption process and surface reaction of the catalyst surface. The binary and ternary catalysts exhibit similar acid properties, but different activity in the SCR reaction, possibly related to the superior redox properties of the WO{sub 3}-containing sample. Over both samples the estimates of the activity energies for NH{sub 3} desorption at zero coverage and for the surface reaction of NO with NH{sub 3} are similar and in the 23--26 and 14--16 kcal/mol ranges, respectively.
- OSTI ID:
- 556742
- Journal Information:
- AIChE Journal, Journal Name: AIChE Journal Journal Issue: 10 Vol. 43; ISSN 0001-1541; ISSN AICEAC
- Country of Publication:
- United States
- Language:
- English
Similar Records
Reducing NO[sub x] in diesel exhausts by SCR technique: Experiments and simulations
Transient kinetics of SO{sub 2} oxidation over SCR-DeNO{sub x} monolith catalysts
Nature of Active Sites and Surface Intermediates during SCR of NO with NH3 by Supported V2O5–WO3/TiO2 Catalysts
Journal Article
·
Mon Oct 31 23:00:00 EST 1994
· AIChE Journal (American Institute of Chemical Engineers); (United States)
·
OSTI ID:6942075
Transient kinetics of SO{sub 2} oxidation over SCR-DeNO{sub x} monolith catalysts
Journal Article
·
Thu Jul 01 00:00:00 EDT 1999
· Industrial and Engineering Chemistry Research
·
OSTI ID:680074
Nature of Active Sites and Surface Intermediates during SCR of NO with NH3 by Supported V2O5–WO3/TiO2 Catalysts
Journal Article
·
Sun Oct 22 20:00:00 EDT 2017
· Journal of the American Chemical Society
·
OSTI ID:1468067