有色设备

VO is one of the most promising energy materials due to its specific physical and chemical properties. Herein, preparation VOvia the reduction of V₂O₃ in an H₂ atmosphere was presented. The thermodynamic calculation was first performed to ensure the reduction conditions and isothermal reduction experiments were then carried out at 1623K, 1648K, and 1673K under a H₂ gas flow. Thermodynamic calculations results indicated that the reduction of V₂O₃ is mainly affected by temperature and p(H₂)/p(H₂O), and the reaction temperature can be typically decreased with increasing p(H₂)/p(H₂O). The results show that the V₂O₃ reduction process conforms to the unreacted shrinkage core model, and the reaction process can be divided into two steps. The first step is controlled by a chemical reaction, the kinetic equation of the reaction is G(α)=[-ln(1-α)]^1/3, and the apparent activation energy is 107.3kJ·mol-1. The second stage is controlled by gas diffusion. The kinetic equation of the reaction isG(α)=[1-(1-α)^1/3]^1/2, and the apparent activation energy is 45.5kJ·mol^-1. No other intermediate compounds were found in this study. The microanalysis indicated that the as-prepared VO powder is well-crystallized and the surface is compact.