The structure and catalytic activity for propylene oxidation of series oxides Bi2Mo3-3x-Nb2xO12-4x (X=0.00, 0.02, 0.05, 0.10, 0.15, 0.20, 0.25) have been studied by means of XRD, IR, Raman, SEM, ESR, etc. The results showed that in the range of X < 0.25 the catalysts possessed a typical a-Bi2Mo3O12 structure, while the oxygen vacancies were formed due to the substitution of Nb5+ for Mo6+, and the concentration of randomly distributed oxygen vacancy passed through a max. at X = 0.15. The catalytic activity was in parallel with the concentration of oxygen vacancy. The catalytic reaction obeyed redox mechanism.

Key words: OXIDATION, PROPENE, NIOBIUM, BISMUTH OXIDE, DOPE, STRUCTURE AND PROPERTY CORRELATION, DOUBLE OXIDE, MOLYBDENUM OXIDE, SCHEELITE, CATALYTIC ACTIVITY