Abstract: Iron-vanadium oxide catalyst (Fe-V-O) samples were prepared by co-precipitation, gel combustion, and hydrothermal method, respectively. The catalytic activity of the as-prepared catalyst in the liquid-phase oxidation of toluene by hydrogen peroxide was tested. In addition, the physicochemical properties of these samples were characterized by N₂ adsorption-desorption, powder X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, and H₂ temperature-programmed reduction. The preparation method significantly affected the structure, specific surface area, morphology, surface V/Fe ratio and reducibility of the as-prepared catalyst samples. Fe-V-O sample prepared by hydrothermal method exhibited the highest benzaldehyde yield and better reusability compared with other investigated samples, due to its smaller particle size, larger specific surface area, higher V/Fe surface ratio and the moderate reducibility.

Key words: iron, vanadium, composite oxide, toluene, liquid-phase oxidation, benzaldehyde