Rapid synthesis of cryptomelane-type manganese oxide under ultrasonic process

摘要

Cryptomelane-type manganese oxide (OMS-2) was rapidly prepared under ultrasonic irradiation in short time. Characterization results using X-ray powder diffraction (XRD), surface area analyzer, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), oxygen temperature-programmed desorption (O_2-TPD) revealed that ultrasonic irradiation has tremendous effect on the surface area, morphology, surface defects, and redox properties of the OMS-2 materials. The OMS-2 prepared via ultrasonic irradiation shows nanoneedle morphology with smaller crystallite size, larger surface area (120.4 m~2/g), more surface defects, and higher oxygen mobility, thus it demonstrates excellent activity in the catalytic combustion of dimethyl ether with a start-off temperature of 160 °C and a complete combustion temperature of 172°C.