PROPENE-V2O5 INTERACTIONS STUDIED BY INFRARED-EMISSION SPECTROSCOPY

Infrared emission spectroscopy was used to investigate the interactions between propene and vanadium hemipentoxide. The spectrum obtained for V2O5 alone was very similar to the spectrum given by KBr disc transmission method. Reaction of propene on V2O5 was performed between 110 and 250°C; IR spectra were recorded in situ. Reduction of the oxide occurred and its bands were strongly altered. The bands attributed to the terminal oxygen (1018 cm-1) and to the doubly bridged oxygen (820 cm-1) were mainly affected by the reaction with propene. For a reaction temperature of 250°C, the recorded spectrum was close to that given by hydrogen reduction at 230°C. It can be concluded that V2O5 was reduced by propene with the formation of a superficial suboxide. By oxygen treatment, the reduced form was restored to the initial V2O5 sample. Infrared emission spectroscopy appears as a very suitable method for studying the interactions of the reactants with the catalysts. © 1979.