CATALYTIC ACTIVITY OF V-Sn OXIDES FOR OXIDATION REACTIONS.

Article abstract of DOI:10.1246/bcsj.54.343

The rate of oxidation of C//3H//6, C//2H//4, C//3H//8, and CO has been investigated over V-Sn oxides of various compositions. The rate shows two maxima at V-Sn(V/Sn equals 2/1) and (1/8) oxides. Comparison between the rate of reduction of the oxides with C//3H//6 and that of the corresponding catalytic oxidation suggests that the oxygen species responsible for oxidation differs for V-Sn(2/1) and V-Sn(1/8) oxides. The amount of oxygen desorbed in the temperature range 400-530 degree C varies with the composition of the V-Sn oxides, showing a maximum at V-Sn(2/1) oxide. With V-Sn(1/8) oxide, little or no oxygen desorption is observed. On the basis of these results together with those of structural studies, it is concluded that the rate maximum with V-Sn(2/1) oxide arises from formation of an amorphous material from which lattice oxygen is easily released, while the rate maximum with V-Sn(1/8) oxide is associated with the presence of V**4** plus ions dissolved in SnO//2.