A series of catalysts, Bi~xPMo~1~2O~y(x=2-9, y=43-64), was synthesized from 12-molybdophosphoric acid in acidic condition. The results indicated that the basic composition of the calcinated catalysts was α-Bi~2Mo~3O~1~2/MoO~3. It was found that with the increase of Bi/P molar ratio, the surface photovoltage spectra (SPS) of the catalysts exhibits regular evolutions characteristic. Another experiments using the samples as catalysts in selective oxidation of propane showed that the content of Bi increased, the amount of cation-flaw as basic capacity in the catalysts decreaed with the A vacancy in scheelite-type oxides (AMO~4) distribution in order. Correspondingly, the shift of P~2 band to negative electric field and decreased of P~1 band, the activity of catalytic decrease, rapidly.

Key words: METALLIC OXIDE CATALYST, BISMUTH OXIDE, PROPANE, MOLYBDENUM OXIDE, SELECTIVE OXIDATION