Abstract:
V
2O
5/Al
2O
3 catalysts with different V
2O
5 mass fraction were prepared with the impregnation method. The support of V
2O
5/Al
2O
3 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), N
2 adsorption-desorption isotherm (BET), H
2 temperature-programmed reduction(H
2-TPR) and NH
3 temperature-programmed desorption (NH
3-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 Al
2O
3, 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%V
2O
5/12%ZrO
2-Al
2O
3, the value of methanol conversion and DMM selectivity were 27.9% and 99.9% at 175 ℃, respectively.