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1585401 
Journal Article 
Aqueous-phase ketonization of acetic acid over Ru/TiO2/carbon catalysts 
Tu Nguyet Pham; Shi, D; Sooknoi, T; Resasco, DE 
2012 
Yes 
Journal of Catalysis
ISSN: 0021-9517
EISSN: 1090-2694 
295 
169-178 
WOS:000310940300016 
The ketonization of acetic acid over Ru/TiO2 and Ru/TiO2/C
catalysts has been accomplished in the liquid phase at temperatures significantly lower than
those typically needed for this reaction. The catalysts were prepared by impregnating the
activated carbon support with titanium(IV) isopropoxide, followed by slow hydrolysis and
calcination in the absence of air. The resulting TiO2/C powder was further impregnated with Ru
(III) chloride, dried, and calcined in air. After an in situ pre-reduction in H-2, the resulting
Ru/TiO2/C exhibited high activity and selectivity to acetone in both organic and aqueous phases
at 180 degrees C. By contrast, when the TiO2/C sample was pre-calcined in air before the addition
of Ru, the resulting catalyst showed significantly lower activity, even when it was pre-reduced
in situ, and was essentially inactive without pre-reduction. It is believed that surface Ti3+
species can be readily formed and favor the ketonization reaction in the presence of liquid
water. A combination of techniques including TEM, BET, TPR, XRD, XPS, and EPR was used to
characterize the reducibility of the catalysts as well as the formation of and stability of Ti3+
sites. It is proposed that the presence of Ru on TiO2 facilitates the formation of these reduced
sites. Furthermore, the hydrophobicity of the carbon support is believed to slow down the typical
inhibiting effect of water for reactions catalyzed by reduced Ti3+ sites. (C) 2012 Elsevier Inc.
All rights reserved. 
Biomass conversion; Acetic acid; Ketonization; Liquid phase reaction