Abstract The effects of Ru precursor, Ru loading, preparative method and calcination temperature on the performances of the Al2O3-supported RuO2(RuO2/Al2O3) catalysts in the selective oxidation of methanol were investigated. Their structures were characterized by X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS), transmission electron microscope(TEM), scanning electron microscope(SEM) and temperature programmed reduction in H2(H2-TPR). The RuO2/Al2O3 catalyst prepared by a deposition-precipitation method and using Ru(NO)(NO3)3 as a precursor after calcination at 500 ℃ showed higher activity and dimethoxymethane selectivity. The dimethoxymethane selectivity reached about 80% when methanol conversion about 20% was at 120 ℃. CH3OH oxidation rate per Ru atom decreased with increasing the Ru loadings. RuO2 existed preferentially in the form of nanorods at the lower Ru loading, which gradually transformed to irregular blocky structures of smaller sizes with increasing the Ru loading. The RuO2 nanorods exhibited superior reducibility and methanol oxidation activity.
