Reduction behavior of tungsten oxide with and without scandia doping

As an important powder material for scandate cathode, Sc2O3-doped WO3 powder together with hollow spherical WO3 for comparison was prepared by spray-drying method. The reduction behavior and kinetics of pure WO3 and Sc2O3-doped WO3 were studied by temperature-programmed reduction (TPR) method. It is found that scandia doping can decrease the reduction activation energy of WO3 and thus lower the reduction temperature and increase the reduction rate. Based on the kinetics results, the reduction techniques are presented. The obtained powder has a narrow size distribution in the range of 0.6–0.8 μm.