V2O5/CeF3 catalysts with 2.4-15.2 wt.% of V2O5 were prepared by wet impregnation method. The catalysts were characterized by BET surface area and pore size distribution, powder X-ray diffraction and FT-IR. It was found that the formation of Cerium Vanadate (CeVO4) occurs during the stages of the catalyst preparation. The X-ray diffraction studies of the catalysts revealed the presence of crystalline CeVO4 phase. The lines due to CeVO4 phase were found to increase in intensity with the increase in amount (wt.%) Of V2O5 in the catalysts. The FT-IR investigation also showed the formation of CeVO4 phase with increasing loadings of V2O5 . The shift of pore-size distribution to lower pore range and increased pore volume confirmed the formation of CeVO4 structure in the catalysts. The catalytic activity for the ammoxidation of 3-picoline to nicotinonitrile on V2O5/CeF3 Catalysts as a function Of V2O5 loading on CeF3 has been studied. The continuous increase of CeVO4 with V2O5 loadings is responsible for the higher ammoxidation activity of the V2O5/CeF3 catalysts. (C) 2004 Elsevier B.V. All rights reserved.