Spectroscopy of mixed molybdenum-vanadium oxides and catalytic oxidation of toluene

The EPR, FTIR, and XRD techniques are used to examine individual and mixed vanadiummolybdenum oxides of composition (1 - x)V2O5: xMoO(3) prepared by coprecipitation. The phase and structural heterogeneity of these oxides is characterized. The oxidation of toluene with air oxygen to maleic anhydride on V2O5 and mixed oxides involves singlet oxygen O-1(2). A correlation between the content of V(IV) ions in the mixed catalysts and the amount desorbed O-1(2) is observed. It is demonstrated that the oxidation of toluene causes changes in the spatial distribution of the V(IV) ions in the matrix and the phase composition of the samples.