Isotopic Oxygen Exchange over Pd/Al2O3 Catalyst: Study on C18O2 and 18O2 Exchange

被引：21

作者：

Ojala, Satu ^{[2
]}

Bion, Nicolas ^{[1
]}

Gomes, Sergio Rijo ^{[1
]}

Keiski, Riitta L. ^{[2
]}

Duprez, Daniel ^{[1
]}

机构：

[1] Univ Poitiers, Dept Chem, Catalyse Chim Organ Lab, F-86022 Poitiers, France

[2] Univ Oulu, Dept Proc & Environm Engn, Lab Mass & Heat Transfer Proc, Oulu 90014, Finland

来源：

CHEMCATCHEM | 2010年 / 2卷 / 05期

基金：

芬兰科学院;

关键词：

isotopic labeling; reaction mechanisms; oxygen; palladium; supported catalysts; SUPPORTED PALLADIUM; CARBONATE FORMATION; SURFACE; REACTIVITY; OXIDATION; ALUMINA; COMBUSTION; OXIDES;

D O I：

10.1002/cctc.201000033

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：

Oxygen mobility on Pd/Al2O3 catalysts in generally considered to be rather slow compared with other noble metal catalysts This study shows that oxygen can be exchanged from gas phase CO2 produced during, for example, methane oxidation more rapidly than from O-2 molecules. The oxygen exchange needs to be carried out in the presence of palladium. However, the presence of Pd on Al2O3 slightly enhances (CO2)-O-18 exchange according to the number of exchanged atoms in the gas phase In this case, the calculation of intial rate for (CO2)-O-18 exchange is not adequate to evaluate oxygen mobility; information on the number of exchange atoms and on the evolution of the concentrations of the different isotopomers is also needed. The enhancement of oxygen exchange is due to carbonate formation on the catalytic surface as evidenced by in situ FTIR spectroscopic measurements. A five-step mechanism is suggested to explain these findings. according to the number of exchanged atoms in the gas

引用

页码：527 / 533

页数：7

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