抄録
Among V2O5 samles prepared at three different temperatures (400, 450 and 500°C), the formation rate of V4O9 was compared in the reduction process with SO2 gas at the temperatures of 350 to 400°C. The rate, increasing with the decrease of the preparation temperature, was not dependent upon the mean diameters of the samples but upon the microtextures of the particles. Crystallite of V2O5 seemed to play the role in the reduction, according to SEM observation and the measurements of BET surface area (S) and of X-ray peak breadth at half maximum intensity (βhoo). TEM observation of this process showed the topotaxy between V205 and V4O9 crystals as follows; [001] V2O5 // [100] V4O9 and the angle between [010] V2O5 and [010] V4O9 was 48°. Then, it can be concluded that V4O9 is introduced by removing every fourth oxide layer of V2O5 crystal, followed by shearing relatively in 1/6 [103] V2O5 direction.
