Characterization of γ-alumina-supported Molybdenum oxide and tungsten oxide; reducibility of the oxidic state versus hydrodesulfurization activity of the sulfided state
Thiophene hydrodesulfurization and butene hydrogenation have been determined for MoO 3 γ- Al 2 O 3 WO 3 γ- Al 2 O 3 , and Re 2 O 7 γ- Al 2 O 3 catalysts, using a microf-low reactor operating at atmospheric pressure. Catalysts have been prepared by various methods, viz., ion exchange, gas-phase adsor...
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Published in | Journal of catalysis Vol. 76; no. 2; pp. 241 - 253 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Elsevier Inc
01.08.1982
|
Online Access | Get full text |
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Summary: | Thiophene hydrodesulfurization and butene hydrogenation have been determined for
MoO
3
γ-
Al
2
O
3
WO
3
γ-
Al
2
O
3
, and
Re
2
O
7
γ-
Al
2
O
3
catalysts, using a microf-low reactor operating at atmospheric pressure. Catalysts have been prepared by various methods, viz., ion exchange, gas-phase adsorption, dry and wet impregnation of γ-Al
2O
3 as well as impregnation of boehmite. The catalysts have been prepared on a surface coverage basis.
The catalysts were characterized by X-ray diffraction, surface area and pore volume measurements, and temperature-programmed reduction (TPR).
MoO
3
γ-
Al
2
O
3
and
WO
3
γ-
Al
2
O
3
catalysts prepared by dry and wet impregnation give essentially the same results.
A correlation exists between the reducibility of oxidic
MoO
3
γ-
Al
2
O
3
and
WO
3
γ-
Al
2
O
3
catalysts prepared by dry and wet impregnation, and the hydrodesulfurization activity of the sulfided samples. The higher the reducibility, the higher the hydrodesulfurization activity. This correlation also holds for
MoO
3
γ-
Al
2
O
3
catalysts prepared by other methods, viz., ion exchange, gas-phase adsorption, and impregnation of boehmite, and for
Re
2
O
7
γ-
Al
2
O
3
catalysts prepared by dry impregnation.
Butene hydrogenation activity of sulfided
MoO
3
γ-
Al
2
O
3
and
WO
3
γ-
Al
2
O
3
catalysts also correlates with reducibility. This correlation is qualitatively the same as that found for hydrodesulfurization. For
Re
2
O
7
γ-
Al
2
O
3
catalysts this is not the case. The ratio between hydrodesulfurization activity and hydrogenation activity decreases in the order W → Mo → Re.
TPR is a time-saving screening technique for unpromoted well-dispersed hydrodesulfurization catalysts. |
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ISSN: | 0021-9517 1090-2694 |
DOI: | 10.1016/0021-9517(82)90255-X |