Synthesis of nanoV 3.6 Mo 2.4 O 16 and their catalytic activity in the selective oxidation of toluene

Abstract

Molybdenum vanadate is a novel vanadate. It is a functional material with good magnetic, electrical and catalytic properties. However, it is rarely used in the selective catalytic oxidation field, while the transition metal molybdenum and vanadium are usually used as a catalytic oxidation catalyst, the complex oxide and salt are naturally concerned. The structure of high-quality single crystalline Molybdenum vanadate (V3 .6Mo2.4O16) nanorods was synthesised by sol–gel method and high-temperature solid-state reaction. The effects of vanadium and molybdenum molar ratio and calcination temperature on the preparation of V3.6Mo2.4O16 were studied. The structure of the catalyst was characterised by X-ray diffraction, thermogravimetry, X-ray photoelectron spectroscopy, scanning electron microscope and transmission electron microscope. The experimental results show that the molar ratio of vanadium–molybdenum is 10:7 when the precursor calcination temperature is 540°C, the single crystalline V3.6Mo2.4O16 nanorods with regular shape has been obtained, the diameter of about 200 nm and the length up to tens of micrometres and the surface is smooth. Catalytic oxidation of toluene to benzaldehyde is used as a probe reaction for nanoV3.6Mo2.4O16. The catalytic activity of the catalyst is good, the conversion of toluene is 39.8% and the selectivity of benzaldehyde is 70.1%.