Comparative study of structural properties and NOx storage-reduction behavior of Pt/Ba/CeO2 and Pt/Ba/Al2O3

被引：37
作者：
Casapu, A. [1 ]
Grunwaldt, J. -D. [1 ]
Maciejewski, M. [1 ]
Krumeich, F. [1 ]
Baiker, A. [1 ]
Wittrock, M. [2 ]
Eckhoff, S. [2 ]
机构：
[1] ETH, Inst Chem & Bioengn, Dept Chem & Appl Biosci, CH-8093 Zurich, Switzerland
[2] Umicore AG & Co KG, D-63403 Hanau, Germany
来源：
APPLIED CATALYSIS B-ENVIRONMENTAL | 2008年 / 78卷 / 3-4期
关键词：
NOx storage-reduction catalyst; ceria; pre-treatment; thermal analysis; X-ray absorption spectroscopy;
D O I：
10.1016/j.apcatb.2007.09.030
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：
Differences in the NOx storage-reduction (NSR) behavior of Pt/Ba/CeO2 and Pt/Ba/Al2O3 have been identified and traced to their different chemical and structural properties. The results show that Pt/Ba/CeO2 exhibits inferior NO, storage and, particularly, reduction (regeneration) activity compared to the Al2O3 supported catalyst. The incomplete reduction of the stored NOx-species in Pt/Ba/CeO2 seems to be caused by a faster and more profound reoxidation of Pt particles during the lean period as evidenced by in situ X-ray absorption spectroscopy. Interestingly, the reduction activity could be significantly improved by a pre-reduction step at mild conditions. Exposure of the Pt/Ba/CeO2 catalyst to reducing H-2 atmosphere in the temperature range 300-500 degrees C lead to a moderate increase of Pt particle size which beneficially influenced the regeneration activity. In contrast, pre-reduction at temperatures above 500 degrees C was unfavorable and resulted in a severe decrease of the regeneration activity, probably due to migration of the partially reduced CeO2 onto the surface of Pt particles. (c) 2007 Elsevier B.V. All rights reserved.
引用
收藏
页码：288 / 300
页数：13
相关论文
共 51 条
[21]   Affinity order among noble metals and CeO2 [J].
Hosokawa, S ;
Taniguchi, M ;
Utani, K ;
Kanai, H ;
Imamura, S .
APPLIED CATALYSIS A-GENERAL, 2005, 289 (02) :115-120
[22]   NO REDUCTION BY CO OVER RH AL2O3 - EFFECTS OF RHODIUM DISPERSION ON THE CATALYTIC PROPERTIES [J].
KASPAR, J ;
DELEITENBURG, C ;
FORNASIERO, P ;
TROVARELLI, A ;
GRAZIANI, M .
JOURNAL OF CATALYSIS, 1994, 146 (01) :136-143
[23]   Use of CeO2-based oxides in the three-way catalysis [J].
Kaspar, J ;
Fornasiero, P ;
Graziani, M .
CATALYSIS TODAY, 1999, 50 (02) :285-298
[24]   Relationship of Pt particle size to the NOx storage performance of thermally aged Pt/BaO/Al2O3 lean NOx trap catalysts [J].
Kim, Do Heui ;
Chin, Ya-Huei ;
Muntean, George G. ;
Yezeretz, Aleksey ;
Currier, Neal W. ;
Epling, William S. ;
Chen, Hai-Ying ;
Hess, Howard ;
Peden, Charles H. F. .
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH, 2006, 45 (26) :8815-8821
[25]   A study of the behaviour of Pt supported on CeO2-ZrO2/Al2O3-BaO as NOx storage-reduction catalyst for the treatment of lean burn engine emissions [J].
Liotta, LF ;
Macaluso, A ;
Arena, GE ;
Livi, M ;
Centi, G ;
Deganello, G .
CATALYSIS TODAY, 2002, 75 (1-4) :439-449
[26]   Novel pulse thermal analysis method and its potential for investigating gas-solid reactions [J].
Maciejewski, M ;
Muller, CA ;
Tschan, R ;
Emmerich, WD ;
Baiker, A .
THERMOCHIMICA ACTA, 1997, 295 (1-2) :167-182
[27]   Mobility of surface species on oxides .1. Isotopic exchange O-18(2) with O-16 of SiO2, Al2O3, ZrO2, MgO, CeO2, and CeO2-Al2O3. Activation by noble metals. Correlation with oxide basicity [J].
Martin, D ;
Duprez, D .
JOURNAL OF PHYSICAL CHEMISTRY, 1996, 100 (22) :9429-9438
[28]   Recent advances in automobile exhaust catalysts [J].
Matsumoto, SI .
CATALYSIS TODAY, 2004, 90 (3-4) :183-190
[29]   THE PASSIVATING OXIDATION OF PLATINUM [J].
MCCABE, RW ;
WONG, C ;
WOO, HS .
JOURNAL OF CATALYSIS, 1988, 114 (02) :354-367
[30]   Sintering inhibition mechanism of platinum supported on ceria-based oxide and Pt-oxide-support interaction [J].
Nagai, Yasutaka ;
Hirabayashi, Takeshi ;
Dohmae, Kazuhiko ;
Takagi, Nobuyuki ;
Minami, Takashi ;
Shinjoh, Hirofumi ;
Matsumoto, Shin'ichi .
JOURNAL OF CATALYSIS, 2006, 242 (01) :103-109
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