Modified Ag/TiO2 systems: Promising catalysts for liquid-phase oxidation of alcohols

• Published in: Fuel (Guildford) Vol. 234; pp. 110 - 119
• Main Authors: Kolobova, E., Kotolevich, Y., Pakrieva, E., Mamontov, G., Farias, M.H., Cortés Corberán, V., Bogdanchikova, N., Hemming, J., Smeds, A., Mäki-Arvela, P., Murzin, D. Yu, Pestryakov, A.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15-12-2018
• Subjects: Alcohols selective oxidation; Betulin oxidation; Effect of redox pretreatment; n-Octanol oxidation; Silver active sites; Silver catalysts; Support modifiers; Support modifiers; Effect of redox pretreatment; n-Octanol oxidation; Alcohols selective oxidation; Silver active sites; Betulin oxidation; Silver catalysts
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/j.fuel.2018.06.128

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•Silver catalysts are promising catalytic system for liquid-phase oxidation of alcohols.•The catalytic behavior of Ag/MxOy/TiO2 depends on the ratio of Ag/Ag+.•Cationic Ag+ species are active sites in both reactions.•Ag/CeO2/TiO2 catalyst displayed the highest activity in both studied reaction.
The current work is the first study concerning the liquid-phase oxidation of n-octanol and betulin over modified and unmodified Ag/TiO2 catalysts. Catalytic activity of nanosilver catalysts supported on titania for alcohols selective oxidation can be enhanced by modification of the support with Ce, Fe or Mg oxides. In most cases reductive or oxidative pretreatments of these catalysts were detrimental for their activity. The main reason for performance of Ag/MxOy/TiO2 catalysts is changes of the electronic state of the supported Ag, and especially changes in the surface concentration of Ag+ ions. Monovalent Ag+ ions are active sites in silver-containing catalysts for n-octanol, as well as for betulin oxidation. The obtained results show a potential of silver-containing catalysts for liquid phase oxidation of alcohols, and by selecting the optimum modifier and the support as well as, pretreatment conditions the catalytic properties and stabilization of the active sites can be optimized.