Microstructural changes in vanadium pentoxide in controlled environments

Direct observations have been made of the reduction of V2O5 between room temperature and ∼600°C in reducing gases such as H2, balanced by He, CO and C2H4, using a gas-reaction cell in a high-voltage electron microscope. The systematic study has revealed microstructural changes relevant to structural and catalytic properties of the system. The reduction of the surface begins at low temperatures of ∼80–100°C. The defect structures formed are analysed, and it is shown that these are important in understanding redox reactions. The results could also perhaps explain chemical studies of oxygen desorption from V2O5.