The Synthesis of Dimethoxymethane through Selective Oxidation of Methanol with V₂O₅/ZrO₂-Al₂O₃ Catalysts

V₂O₅/Al₂O₃ catalysts with different V₂O₅ mass fraction were prepared with the impregnation method. The support of V₂O₅/Al₂O₃ catalyst was modified with Zr. The catalysts were applied to the selective oxidation of methanol to prepare dimethoxymethane(DMM). The as-prepared catalysts were characterized with X-ray diffraction(XRD), scanning electron microscope (SEM), ultraviolet and visible spectrophotometry (UV-Vis), fourier transform infrared (FTIR), raman spectra (Raman), N₂ adsorption-desorption isotherm (BET), H₂ temperature-programmed reduction(H₂-TPR) and NH₃ temperature-programmed desorption (NH₃-TPD). The results indicated that the performance of Zr modification could effectively improve the dispersibility and stability of vanadium oxide and the interaction between the substances in the catalyst. In addition, compared with vanadium-based catalysts supported on the single oxide Al₂O₃, the Zr modification could effectively regulate the acidity and oxidation properties of the catalyst, which improved the selectivity of DMM. The effect of reaction conditions on the preparation of DMM through methanol oxidation was investigated. For the catalyst 20%V₂O₅/12%ZrO₂-Al₂O₃, the value of methanol conversion and DMM selectivity were 27.9% and 99.9% at 175 ℃, respectively.