Study of microstructure and catalytic activity of γ-Bi2MoO6 and Bi2WO6 compounds

Bi2MO6 (M=Mo, W) compounds were prepared for low-temperature oxidation. The catalysts were prepared by solid-state reaction. The structural changes were followed by X-ray diffraction, scanning electron microscopy, Auger electron spectroscopy and BET nitrogen absorption. Auger analysis shows that Bi2WO6 catalysts have more bismuth on the surface than gamma-Bi2MoO6, although both samples are bismuth deficient as compared to the stoichiometric compound. The results regarding catalytic activity show that Bi2WO6 prepared at 1073 K reaches total conversion of CO (100%) at a lower temperature when compared to gamma-Bi2MoO6. This indicates that Bi2WO6 is a potential candidate to be used as catalyst in the CO to CO2 oxidation.