EFFECT OF THE ADDITION OF MO AND NA TO PT CATALYSTS ON THE SELECTIVE REDUCTION OF NO

Citation
T. Tanaka et al., EFFECT OF THE ADDITION OF MO AND NA TO PT CATALYSTS ON THE SELECTIVE REDUCTION OF NO, Applied catalysis. B, Environmental, 16(3), 1998, pp. 199-208
Citations number
32
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Chemistry Physical","Engineering, Environmental
ISSN journal
0926-3373
Volume
16
Issue
3
Year of publication
1998
Pages
199 - 208
Database
ISI
SICI code
0926-3373(1998)16:3<199:EOTAOM>2.0.ZU;2-7
Abstract
The selective reduction of NOx by reductants such as C3H6 and CO in ox idizing feedstreams simulated exhaust from automobile engine and three -way behavior around the stoichiometric point have been investigated o n trimetallic PtMoNa/SiO2 catalysts, over a wide range of temperatures compared with bimetallic PtMo/SiO2 catalyst and monometallic Pt/SiO2 catalyst. The simultaneous addition of Mo and Na to Pt catalysts has b een found to improve the following reaction characteristics on selecti ve reduction of NOx and three-way activity of conventional Pt catalyst . The temperature window on selective reduction of NOx on trimetallic PtMoNa/SiO2 catalysts was found to be wider and to shift at higher tem perature than that on bimetallic PtMo/SiO2 and monometallic Pt/SiO2 ca talysts under lean static conditions. The redox ratio window, in which three-way activity occurred on trimetallic PtMoNa/SiO2 catalysts, was also found to be wider than that on bimetallic PtMo/SiO2 catalysts an d monometallic Pt/SiO2 around stoichiometric point. On the other hand, XPS, IR and CO adsorption data indicated that the oxidation of Pt on PtMoNa/SiO2 catalysts was depressed by the added Mo and Na even under excess oxygen conditions, so that the reaction characteristics of trim etallic PtMoNa/SiO2 catalysts was improved. (C) 1998 Elsevier Science B.V.