Abstract: V_2O_5 supported on various TiO_2 including anatase, rutile and mixture of both types have been investigated with various physicochemical measurements such as BET, TPD, NARP, XRD and so on. It has been found that the V=O species or the (010) plane of V_2O_5 on all the TiO_2 supports with large BET surface area are selectively exposed to the surface, though different modifications of TiO_2 results in different characteristics of exposure of (010) plane. For anatase, the maximum exposure of the V=O species is obtained at the surface concentration of V_2O_5 significantly lower than that for rutile. For the mixture, two maxima are obtained in the surface concentration of V_2O_5 corresponding to those for anatase and rutile respectively. Thus, it is concluded that crystal structure of the TiO_2 support determines the maximum exposure of (010) plane. The chemical activity of TiO_2 surface also seems to have an effect on the exposure of (010) plane. That is, the higher surface area and the stronger acidic property resulted in the high exposure of (010) plane.

Key words: V₂O₅, TiO₂, Interaction, Crystal structure