Nanocomposites SnO2/Fe2O3: Sensor and catalytic properties

Abstract Nanocomposites SnO 2 /Fe 2 O 3 have been obtained in whole concentration range (0–100 mol% Fe 2 O 3 ) using wet chemical synthesis. The gas sensor properties of nanocomposites towards CO (40–150 ppm), ethanol (10–200 ppm), H 2 S (2–10 ppm) and NO 2 (50 ppb–10 ppm) have been studied by conductance measurements in temperature range 150–450 °C. Balancing the SnO 2 /Fe 2 O 3 molar ratio sensors performances can be tailored to obtain materials suitable for different applications. High responses towards ethanol together with low humidity effects have been observed for samples with a high Fe 2 O 3 content ( x  > 70 mol%). Acidic and redox properties of the samples were characterized by NH 3 -TPD and H 2 -TPR, respectively. Catalytic properties of nanocomposites were studied in ethanol oxidation using continuous-flow catalytic system. It is demonstrated that increase of Fe 2 O 3 content reduces the amount of surface acid sites and enhances the oxidizing capability of nanocomposites in ethanol oxidation.