The effect of the morphological characteristics of a TiO2 support on the reverse water-gas shift reaction over Pt/TiO2 catalysts was examined. The activity of Pt catalysts with 6 different types of TiO2 supports varied during the reverse water-gas shift reaction. Analysis using H-2 Temperature Programmed Reduction (TPR) and Temperature Programmed Desorption (TPD) confirmed that the active sites of the Pt/TiO2 catalyst included both the Pt sites and the TiO2 sites, which were reducible, and the difference in the activity of the Pt/TiO2 catalysts was dependent on the reducibility of the TiO2 supports. X-ray diffraction (XRD) analysis showed that the TiO2 crystallite size was a key factor that dictated the reducibility of the TiO2 sites. (C) 2012 Elsevier B.V. All rights reserved.