Promotive effect of Bi component on propane partial oxidation over MoBiTeOx/SiO2 catalysts

A series of MoTeOx/SiO2 and MoBiTeOx/SiO2 catalysts was prepared and catalytic performance of propane partial oxidation to acrolein was tested. The addition of low amount of Bi component to MoTeOx/SiO2 catalysts was found to significantly promote acrolein selectivity. The catalyst structure and redox properties were investigated by means of X-ray powder diffraction. Raman spectroscopy, in situ Raman spectroscopy, X-ray photoelectron spectroscopy, and H-2-TPR techniques. Results indicate that the Bi promotive effect can be attributed to two possible reasons. One is that the Bi component promotes the dispersal of MoO3. The isolation effect results in acrolein selectivity increase. Another reason is that Bi doping enhances lattice oxygen diffusion and increases the amount of surface active oxygen, which is responsible for the oxidation of intermediate propylene to acrolein. (C) 2010 Elsevier B.V. All rights reserved.