V-Sb-Oxide catalysts were prepared by SS (solid solution) and CP (co-precip
itation) methods, and the involvement of redox sites and acid sites in the
ammoxidation of propane were investigated by BET, XRD, XPS, NARP (Nitric ox
ide-Ammonia Rectangular Pulse) and NH3-TPD methods. Both series of catalyst
s mainly consisted of the SbVO4 phase with minor components of V2O5 and alp
ha -Sb2O4 phases. The reaction rate of propane ammoxidation increased linea
rly with the increase in the number of redox sites measured by NARP techniq
ue. There was no significant effect of strength and amount of acid sites on
the activity of propane ammoxidation at low conversion levels. The number
of redox sites is the determining factor for ammoxidation activity. V-Sb-Ox
ide catalysts with excess alpha -Sb2O4 phase exhibited higher turnover freq
uency.