1. Nanostructured MnOx catalysts in the liquid phase selective oxidation of benzyl alcohol with oxygen: Part I. Effects of Ce and Fe addition on structure and reactivity.
- Author
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Arena, Francesco, Gumina, Bianca, Lombardo, Agata F., Espro, Claudia, Patti, Antonio, Spadaro, Lorenzo, and Spiccia, Leone
- Subjects
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NANOSTRUCTURED materials , *MANGANESE oxides , *MANGANESE catalysts , *BENZYL alcohol , *OXYGEN , *CERIUM , *ADDITION reactions , *REACTIVITY (Chemistry) - Abstract
The effects of Ce (Ce at /Mn at , 0–1) and Fe addition ((Ce at + Fe at )/Mn at , 0.3) on the texture, structure and redox properties of MnO x systems have been investigated. Irrespective of their loading, the Ce and Fe promoters lead to nanostructured composite systems with a much larger surface area than the oxide component alone. Both Ce and Fe ions improve catalyst reducibility because of structural effects enhancing the surface availability of high oxidation number Mn n+ ( n ≥ 4) sites. At variance with the inactivity of the CeO 2 and Fe 2 O 3 promoters, the bare and promoted MnO x catalysts drive the liquid phase oxidation of benzyl alcohol with oxygen in the range of 323–353 K with total aldehyde selectivity. The dependence of activity level on MnO x loading and unchanging activation energy barrier (52 ± 5 kJ/mol) substantiate the lack of electronic effects attributable to both Ce and Fe promoters. Although a marked activity loss recorded after the 1st reaction cycle, calcination at T ≥ 473 K fully restores the catalyst functionality. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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