The Role of Different Types of CuO in CuO-CeO2/Al2O3 for Total Oxidation

被引：30

作者：

Galvita, Vladimir V. ^{[1
]}

Filez, Matthias ^{[1
]}

Poelman, Hilde ^{[1
]}

Bliznuk, Vitaliy ^{[2
]}

Marin, Guy B. ^{[1
]}

机构：

[1] Univ Ghent, Chem Technol Lab, B-9052 Ghent, Belgium

[2] Univ Ghent, Dept Mat Sci & Engn, B-9052 Ghent, Belgium

来源：

CATALYSIS LETTERS | 2014年 / 144卷 / 01期

关键词：

CuO; Solid solution of copper in ceria; Total oxidation; VOCs; Carbon monoxide; In situ XRD; EXAFS modeling; X-RAY-ABSORPTION; VOLATILE ORGANIC-COMPOUNDS; COPPER-OXIDE CATALYSTS; CO OXIDATION; CARBON-MONOXIDE; ETHYL-ACETATE; MIXED-OXIDE; F-TEST; REDUCTION; SPECTROSCOPY;

D O I：

10.1007/s10562-013-1144-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：

Different types of copper oxide in CuO-CeO2/Al2O3 were investigated structurally and catalytically. Standard preparation lead to the presence of CuO monocrystals and Ce1-xCuxO2-x as evidenced by XRD, HRTEM and EDX. Washing with nitric acid removed the monocrystals, while leaving the Ce1-xCuxO2-x solid solution. The Fourier transformed Cu K patterns for the HNO3-washed catalyst showed a diminished second Cu shell, characteristic for Ce1-xCuxO2-x as well as for X-ray amorphous nano-sized CuAl2O4 spinel phase. XANES analysis and first shell Cu fitting confirmed this CuAl2O4 like structure outside Ce1-xCuxO2-x. By modeling the Ce K EXAFS signal in the washed sample, the amount of Cu in Ce1-xCuxO2-x was determined to be 18 +/- 6 %. Total oxidation of CO and C3H8 as model reactions showed little difference in activity between non-washed and washed CuO-CeO2/Al2O3, indicating that CuO monocrystals were hardly active at temperatures below 450 degrees C. XRD performed in situ during TPR and TPO showed that CeO2 in Ce1-xCuxO2-x added to the redox capacity of both CuO-CeO2/Al2O3 samples as it was partially reduced at 300 degrees C. At higher temperatures, the CuO monocrystals also participated in reaction, leading to a higher activity for the oxidation of CH4.

引用

页码：32 / 43

页数：12

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