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• Novel mesoporous MnO 2 /SnO 2 catalysts prepared by ultrasonic co-precipitation method. • H 2 O 2 decomposition on mixed oxides MnO 2 /SnO 2 was greater than single oxides. • The best MnO 2 /SnO 2 catalyst sonicated at power of 60% for 30 min (MnSnO US(60%)30) • MnSnO US(60%)30 catalyst had the highest S BET and smallest average particle diameter. • MnSnO US(60%)30 sample used as a reusable active catalyst for H 2 O 2 decomposition. Novel mesoporous MnO 2 /SnO 2 catalysts were successfully synthesized via traditional and ultrasonic co-precipitation methods. Moreover, their catalytic efficiencies were evaluated in decomposition of hydrogen peroxide (H 2 O 2). Interestingly, it was found that the mixing of MnO 2 with SnO 2 catalyst led to a significant improvement in their catalytic efficiencies compared with single oxides catalysts. However, the influence of ultrasonic power and irradiation time on MnO 2 /SnO 2 nanomaterials were compared to get optimum synthetic condition. Subsequently, the catalysts were characterized by X-ray diffraction (XRD), N 2 adsorption-desorption analysis and high-resolution transmission electron microscopy (HR-TEM). Results represented that the effect of ultrasonic power and irradiation time on MnO 2 /SnO 2 catalysts exerted a great influence on the BET surface area and average particle diameter. Furthermore, the results showed that the best catalytic efficiency was obtained for the mesoporous MnO 2 /SnO 2 catalyst which is sonicated at power of 60% for 30 min as optimum conditions. Finally, the outcomes appeared that the catalysts synthesized by ultrasonic co-precipitation method were more efficient than those synthesized by traditional co-precipitation in catalyzing H 2 O 2 decomposition. [ABSTRACT FROM AUTHOR]

FeO/MgO systems were prepared by the incipient impregnation, coprecipitation, and hydrothermal techniques. The solids obtained were calcined at 500-900 °C then characterized by use of XRD and EDX, by measurement of specific surface area ( S), and by use as catalysts for HO decomposition. The catalysts contained the nanosized MgO phase in addition to the MgFeO phase. The concentration of surface iron species was highest for catalysts prepared by the coprecipitation method; these catalysts also had the highest specific surface area. The lattice constant of the MgO lattice in the FeO/MgO system depends on both the method of preparation and calcination temperature. Catalysts prepared by the hydrothermal method were most active in HO decomposition. The apparent activation energy and the mechanism of this reaction were not altered by variation of the method of preparation. [ABSTRACT FROM AUTHOR]

Highlights: [•] Preparation and characterization nano-sized Fe2O3/MgO system. [•] Impregnation, coprecipitation and hydrothermal methods are used for preparation. [•] H2O2 decomposition is sensitive to surface concentration of active species. [•] Methanol conversion is sensitive to solid–solid interactions. [•] All catalysts are highly selective to formaldehyde at 300°C. [•] The catalysts are active and stable even after their recycling two times. [ABSTRACT FROM AUTHOR]