Surface and structural characterization of ZrO2–CeO2-supported molybdenum oxide catalysts

Molybdenum oxides supported, on different ratios, over Zr-Ce mixed oxides with general formula ZrxCe(1-x)O2, where x = 0.75 and 0.5, have been prepared and tested in the catalytic combustion of aromatic polycyclic molecules. The morphologic-structural characterization, performed by conventional solid state techniques (XRD, SBET, DTA-TG, FT-IR and DR-UV-vis spectroscopies) evidences that these catalysts, after calcination at 600 deg C, are composed of Mo(VI) oxides supported over a Zr-Ce mixed oxide-phase with varying stoichiometry and symmetry (cubic for high Ce contents and tetragonal for lower Ce contents). All of them are structural and morphologically stable under the operating conditions and display reasonable specific surface area values between 22 and 45 m2 g-1. Catalytic tests indicate that these systems are active in the combustion of aromatic polycyclic molecules.