Surface structure and catalytic performance of niobium oxides supported on titania

Thomas Onfroy (1) , Olga Manoilova , Saeed Bukallah , David Hercules , Guillaume Clet (1) , Marwan Houalla (1)

1 LCS - Laboratoire catalyse et spectrochimie

The surface structure and activity of catalytic systems based on niobium oxide supported on titania were investigated. A series of catalysts with Nb content up to 3.6 atoms/nm2 was prepared by incipient wetness impregnation of the titania support with niobium oxalate solutions. Characterization of the system by X-ray diffraction (XRD) and Raman spectroscopy studies did not show evidence of niobium oxide formation. Surface analysis was performed by X-ray photoelectron spectroscopy (XPS), ion scattering spectroscopy (ISS), Raman and infrared spectroscopy. These results were correlated with Brønsted acidity and catalytic activity determined in our previous study. A direct correlation between the catalytic activity and the abundance of Brønsted acid sites had been observed. Analysis of the surface structure by infrared spectroscopy showed a similar evolution for the intensity of the band attributed to polymerized NbOx.

Domaines: Catalyse

Thomas Onfroy, Olga Manoilova, Saeed Bukallah, David Hercules, Guillaume Clet, et al.. Surface structure and catalytic performance of niobium oxides supported on titania. Applied Catalysis A : General, 2007, 316 (2), pp.184-190. ⟨10.1016/j.apcata.2006.09.021⟩. ⟨hal-03379965⟩