Active oxygen from CeO2 and its role in catalysed soot oxidation

被引:139
作者
Bueno - López, A [1 ]
Krishna, K [1 ]
Makkee, M [1 ]
Moulijn, J [1 ]
机构
[1] Delft Univ Technol, DelftChemTech, NL-2628 BL Delft, Netherlands
关键词
active oxygen; ceria; oxidation; oxygen exchange; soot; temporal analysis of products;
D O I
10.1007/s10562-005-2120-x
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
An advanced TAP reactor is used for the first time to study CeO2 catalysed soot oxidation using labelled oxygen. In the absence of catalyst oxidation takes place above 500degreesC and mainly labelled oxidation species (CO and CO2) were observed. In the presence of catalyst it is shown that the gas-phase labelled oxygen replaces non-labelled lattice oxygen of CeO2 creating highly active oxygen. This highly active non-labelled oxygen reacts with soot giving CO and CO2. The creation of such active oxygen species starts from 400degreesC and it will decrease the soot oxidation temperature. The rate of gas-phase oxygen exchange by the CeO2 lattice oxygen and the rate of this very active lattice oxygen with soot are much faster than the reaction rate of O-18(2) reacting with soot directly. Similarly the rate of active oxygen reaction with soot is much faster than the rate of its combination giving gas-phase O-2.
引用
收藏
页码:203 / 205
页数:3
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