HYDROGEN TEMPERATURE-PROGRAMMED REDUCTION BASED ON WATER ANALYSIS - APPLICATION TO VANADIUM PENTOXIDE

Profiles of temperature programmed reduction (TPR) of V2O5 under H-2 h ave been studied through water analysis. This new approach enhances th e sensitivity of the method. The influence of experimental parameters on the temperature corresponding to the maximum reduction rate, T(m), has been studied. The hydrogen concentration and heating rate are the two major factors that influence T(m). In our method, the amount of so lid and the flow rate are also important fact n monitoring of profile distortions attributed to water condensation at the outlet of the reac tor. An approach of the mechanism of reduction of V2O5 has been carrie d out. The best kinetic model which describes the reduction process is the Avrami-Erofeev tridimensional nucleation model.