Oxygen exchange mechanism between isotopic CO2 and Pt/CeO2

被引：40

作者：

Bueno-Lopez, A. ^{[1
]}

Krishna, K. ^{[1
]}

Makkee, M. ^{[1
]}

机构：

[1] Delft Univ Technol, Delftchem Tech, NL-2628 BL Delft, Netherlands

来源：

APPLIED CATALYSIS A-GENERAL | 2008年 / 342卷 / 1-2期

关键词：

cerium oxide; carbon dioxide; isotopic oxygen exchange; TAP; isotope;

D O I：

10.1016/j.apcata.2008.03.013

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 oxygen exchange mechanism between (CO2)-O-18 and Ceo(2) and the role of Pt in this process have been studied in an advanced TAP reactor in the 200-600 degrees C temperature range. For bare and Pt-containing CeO2, the exchange of the oxygen atoms Of (CO2)-O-18 takes place in the whole temperatures range studied, and the oxygen exchange rate increases with temperature. The proposed mechanistic pathway consists of the exchange of the oxygen atoms in the (CO2)-O-18 Molecule in two consecutive steps. In the case of bare CeO2, only one of the oxygen atoms Of (CO2)-O-18 is exchanged between 200 and 300 degrees C, and temperatures above 300 degrees C are required for the exchange of the second oxygen atom of the (CO2)-O-18 molecule. Pt accelerates the exchange rate between 200 and 400 degrees C, mainly favouring the exchange of the second oxygen atom of the (CO2)-O-18 molecule. The effect of Pt cannot be resolved at higher temperature (above 400 degrees C), since at high temperature the direct exchange over bare CeO2 is already fast. (c) 2008 Elsevier B.V. All rights reserved.

引用

页码：144 / 149

页数：6

共 18 条

[1] IR study of polycrystalline ceria properties in oxidised and reduced states [J].

Binet, C ;

Daturi, M ;

Lavalley, JC .

CATALYSIS TODAY, 1999, 50 (02) :207-225

[2] On the mechanism of model diesel soot-O2 reaction catalysed by Pt-containing La3+-doped CeO2 a TAP study with isotopic O2 [J].

Bueno-Lopez, A. ;

Krishna, K. ;

van der Linden, B. ;

Mul, G. ;

Moulijn, J. A. ;

Makkee, M. .

CATALYSIS TODAY, 2007, 121 (3-4) :237-245

[3] Active oxygen from CeO2 and its role in catalysed soot oxidation [J].

Bueno - López, A ;

Krishna, K ;

Makkee, M ;

Moulijn, J .

CATALYSIS LETTERS, 2005, 99 (3-4) :203-205

[4] Oxygen-18 isotope exchange and equilibration processes over preoxidised and promoted ceria.: Part I.: 15N18O(g) or (18O2+16O2(g)) [J].

Cunningham, J ;

Farrell, F ;

Gibson, C ;

McCarthy, J .

CATALYSIS TODAY, 1999, 50 (02) :429-443

[5] Effect of CeO2 loading on the surface and catalytic behaviors of CeO2-Al2O3-supported Pt catalysts [J].

Damyanova, S ;

Bueno, JMC .

APPLIED CATALYSIS A-GENERAL, 2003, 253 (01) :135-150

[6] The oxidizing role of CO2 at mild temperature on ceria-based catalysts [J].

Demoulin, O. ;

Navez, M. ;

Mugabo, J. -L. ;

Ruiz, P. .

APPLIED CATALYSIS B-ENVIRONMENTAL, 2007, 70 (1-4) :284-293

[7] Reforming of methane with carbon dioxide to synthesis gas over supported rhodium catalysts .2. A steady-state tracing analysis: Mechanistic aspects of the carbon and oxygen reaction pathways to form CO [J].

Efstathiou, AM ;

Kladi, A ;

Tsipouriari, VA ;

Verykios, XE .

JOURNAL OF CATALYSIS, 1996, 158 (01) :64-75

[8] A comparative study of water-gas-shift reaction over ceria supported metallic catalysts [J].

Hilaire, S ;

Wang, X ;

Luo, T ;

Gorte, RJ ;

Wagner, J .

APPLIED CATALYSIS A-GENERAL, 2001, 215 (1-2) :271-278

[9] A model of oxygen transport in Pt/ceria catalysts from isotope exchange [J].

Holmgren, A ;

Duprez, D ;

Andersson, B .

JOURNAL OF CATALYSIS, 1999, 182 (02) :441-448

[10] Interactions of CO with Pt/ceria catalysts [J].

Holmgren, A ;

Andersson, B ;

Duprez, D .

APPLIED CATALYSIS B-ENVIRONMENTAL, 1999, 22 (03) :215-230

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