Systematic mechanism study of the high temperature SCR of NOX by NH3 over a W/TiO2 catalyst

In this study, the reaction mechanism for the high temperature selective catalytic reduction of NO by NH3 over a W/TiO2 catalyst was investigated. A systematic mechanistic pathway for the reaction was proposed based on the results of transient response analysis (TRA), infrared spectroscopy (IR), tem...

Full description

Saved in:
Bibliographic Details
Published in:Chemical engineering science 2012-09, Vol.79, p.177-185
Main Authors: Moon Lee, Sang, Su Kim, Sung, Chang Hong, Sung
Format: Article
Language:English
Subjects:
Ammonia
Applied sciences
Atmospheric pollution
Catalysis
Catalysts
Catalytic reactions
Chemical engineering
Chemistry
Exact sciences and technology
FTIR
General and physical chemistry
General processes of purification and dust removal
Infrared radiation
Infrared spectroscopy
Lewis acid
NH3-SCR
NO removal
oxygen
Pollution
Prevention and purification methods
Reactors
Selective catalytic reduction
temperature
Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
Titanium dioxide
TPR
TRA
W/TiO2
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:In this study, the reaction mechanism for the high temperature selective catalytic reduction of NO by NH3 over a W/TiO2 catalyst was investigated. A systematic mechanistic pathway for the reaction was proposed based on the results of transient response analysis (TRA), infrared spectroscopy (IR), temperature programmed reaction (TPR) and O2 shut-off tests. These experimental results showed that during the initial SCR reaction step, ammonia was adsorbed first and activated at Lewis acid sites (W=O), and then was decomposed into N2 and H2O by gaseous NO+O2. During the redox reaction, gaseous oxygen was involved in the reaction, whereas the effect of catalytic lattice oxygen was very slight (WO3→WO2.9X). Therefore, these findings provide important information to better understand the mechanism responsible for high temperature SCR. [Display omitted] ► The high temperature SCR model using W/TiO2 catalyst follows the E-R model. ► The initial step is the absorption of ammonia on the W=O sites. ► The adsorbed ammonia reacts with gaseous NO and O2. ► The participation of moisture and lattice oxygen on the reaction slightly affected.
ISSN:0009-2509
1873-4405
DOI:10.1016/j.ces.2012.05.032