Electrical and catalytic properties of SnO2/TiO2 measured in operando conditions

The electrical conductivity and the catalytic activity of SnO2 loaded TiO2 (anatase) particles were investigated in operando conditions. SnO2 depositions over commercial TiO2 samples (Sigma Aldrich and Rhone Poulenc) were obtained by the impregnation method. The samples were characterized by XRD, SEM/EDX and BET-N-2 adsorption techniques. The AC electrical conductivity of the samples were measured between 25 and 400 degrees C under various atmospheres. The effect of the reactant mixture on the electrical conductivity and the catalytic performances of the samples were tested in propene oxidation. The results showed that the conductivity of SnO2/TiO2 samples depends strongly on the surface area of TiO2 support. The reducing effect of propene is more evident for higher surface area catalysts, these one showing also higher activity. On the other hand, the SnO2 deposition results in an increase of catalytic performances

The effect of Pt addition on the redox behaviour of V2O5/γ-Al2O3 catalysts measured by an operando electrical conductivity method

Internationa

CO sensing properties of SnO2-CeO2 mixed oxides

SSCI-VIDE+ATARI+GPOInternational audienc

In situ electrical conductivity study of Pt-impregnated VOx/gamma-Al2O3 catalysts in propene deep oxidation

A series of Pt-VOx/gamma-Al2O3 catalysts with vanadium loading corresponding to 5 and 20 wt% V2O5 was prepared by impregnation method. The catalytic performance of the obtained materials was investigated in propene deep oxidation reaction. The catalysts were characterized by N-2 physisorption, chemical analysis, X-ray diffraction (XRD), temperature-programmed reduction (TPR), electron paramagnetic resonance (EPR) spectroscopy, and UV-Vis diffuse reflectance spectroscopy. Alternating current (AC) electrical conductivity measurements (differential steps technique) were performed in situ during propene oxidation, using an own design reactivity cell. The variation in the measured electrical conductance brings information about the relative oxidation state of the catalyst's surface during reaction. It was found by TPR, EPR, and UV-Vis that the presence of platinum facilitates the reduction of V5+ to V4+ species. The catalytic performance of the investigated catalysts was discussed in relation to their structure, reducibility, and conductance