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篇目详细内容 |
【篇名】 |
The state of the dispersed niobia species on γ-Al2O3 and their catalytic performance for the condensation of isobutylene and isobutyraldehyde |
【刊名】 |
Frontiers of Chemistry in China |
【刊名缩写】 |
Front. Chem. China |
【ISSN】 |
1673-3495 |
【EISSN】 |
1673-3614 |
【DOI】 |
10.1007/s11458-009-0111-y |
【出版社】 |
Higher Education Press and Springer-Verlag Berlin
Heidelberg |
【出版年】 |
2010 |
【卷期】 |
5
卷1期 |
【页码】 |
109-112
页,共
4
页 |
【作者】 |
Jie HE;
Yining FAN;
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【关键词】 |
niobia; alumina; dispersion capacity; acidity; olefin-aldehyde condensation |
【摘要】 |
Catalysts of Nb2O5/γ-Al2O3 were prepared by aqueous solution impregnation. The state of niobia species on surface of γ-Al2O3 is characterized by using the technology of X-ray power diffraction (XRD) and analyzed using the “incorporation model”. The acidity and the nature of acid sites of the catalysts were evaluated by means of Fourier transform infrared (FT-IR) spectroscopy of adsorbed pyridine. The catalytic activity of Nb2O5/γ-Al2O3 catalysts was evaluated by a condensation reaction from isobutene and isobutyraldehyde to 2,5-dimethyl-2,4-hexadiene. The results of XRD indicate that the dispersion capacity of niobia on γ-Al2O3 is about 0.76mmol Nb per 100m2 γ-Al2O3, which is almost identical to the theoretical value (0.75mmol Nb per 100m2 γ-Al2O3) calculated by the “incorporation model”. The results of Py-IR and catalytic activity evaluation indicate that the acidity feature is related to the state of dispersed niobia species as well as the loading of niobia onto the surface of γ-Al2O3 support. |
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