Effect of H2 admixture on the adsorption of NO, NO2 and propane at Ag/Al2O3 catalyst as examined by in situ FTIR

被引:57
作者
Bentrup, U [1 ]
Richter, M [1 ]
Fricke, R [1 ]
机构
[1] Adlershof eV, Inst Angew Chem Berlin, D-12489 Berlin, Germany
关键词
NO; NO2; propane; Ag/Al2O3; in situ FTIR spectroscopy;
D O I
10.1016/j.apcatb.2004.08.007
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
The interaction of DeNO(x) components comprising NO, NO2, propane, O-2 and H-2 with a selected Ag/Al2O3 catalyst was studied by in situ FTIR spectroscopy at a fixed temperature where a promoting effect of H-2 admixture on the catalytic NOx reduction has been reported to occur. The significant enhancement of nitrato and acetate ad-species from NO and propane, respectively, could be confirmed. New findings are the relative inertness of these species for further reaction progress. Instead, nitrite, nitrito, and nitro species are reactive, and the H-2 co-fed favours the formation of those species. Nevertheless, the way H-2 interferes with the kind of species formed includes the promotion of oxidative reaction steps evidenced by different effect of H-2 on the interaction of the catalyst with NO/O-2 and NO2, respectively. During NO2/H-2 adsorption adsorbed NOx species and Ag+ ions at the surface are reduced. This prevents abundant formation of stable nitrato species and favour the formation of largely unstable but reactive nitro and nitrito species. Otherwise, NO2 is able to oxidize pre-reduced Ag/Al2O3. Furthermore, indications were found for minor propene formation from propane in the presence of hydrogen. (C) 2004 Elsevier B.V. All rights reserved.
引用
收藏
页码:213 / 220
页数:8
相关论文
共 26 条
[1]   Supported Ag catalysts for the lean reduction of NO with C3H6 [J].
Bethke, KA ;
Kung, HH .
JOURNAL OF CATALYSIS, 1997, 172 (01) :93-102
[2]   Study by in situ FTIR spectroscopy of the SCR of NO, by ethanol on Ag/Al2O3 -: Evidence of the role of isocyanate species [J].
Bion, N ;
Saussey, J ;
Haneda, M ;
Daturi, M .
JOURNAL OF CATALYSIS, 2003, 217 (01) :47-58
[3]  
BRUCKNER A, 2001, P N AM CAT SOC TOR, P236
[4]   A review of the selective reduction of NOx, with hydrocarbons under lean-burn conditions with non-zeolitic oxide and platinum group metal catalysts [J].
Burch, R ;
Breen, JP ;
Meunier, FC .
APPLIED CATALYSIS B-ENVIRONMENTAL, 2002, 39 (04) :283-303
[5]  
Davydov A.A., 2003, MOL SPECTROSCOPY OXI, P124
[6]   Identification of neutral and charged NxOy surface species by IR spectroscopy [J].
Hadjiivanov, KI .
CATALYSIS REVIEWS-SCIENCE AND ENGINEERING, 2000, 42 (1-2) :71-144
[7]   In situ Fourier transform infrared study of the selective reduction of NO with propene over Ga2O3-Al2O3 [J].
Haneda, M ;
Bion, N ;
Daturi, M ;
Saussey, J ;
Lavalley, JC ;
Duprez, D ;
Hamada, H .
JOURNAL OF CATALYSIS, 2002, 206 (01) :114-124
[8]   Nature and catalytic role of active silver species in the lean NOx reduction with C3H6 in the presence of water [J].
Iglesias-Juez, A ;
Hungría, AB ;
Martínez-Arias, A ;
Fuerte, A ;
Fernández-García, M ;
Anderson, JA ;
Conesa, JC ;
Soria, J .
JOURNAL OF CATALYSIS, 2003, 217 (02) :310-323
[9]   Selective catalytic reduction of NOx with CH3OH, C2H5OH and C3H6 in the presence of O2 over Ag/Al2O3 catalyst:: Role of surface nitrate species [J].
Kameoka, S ;
Ukisu, Y ;
Miyadera, T .
PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 2000, 2 (03) :367-372
[10]   Effect of ex situ treatments with SO2 on the activity of a low loading silver-alumina catalyst for the selective reduction of NO and NO2 by propene [J].
Meunier, FC ;
Ross, JRH .
APPLIED CATALYSIS B-ENVIRONMENTAL, 2000, 24 (01) :23-32