【摘要】 <正> 载体TiO₂与某些活性组份有强烈的相互作用,使催化剂具有独特的性能.例如,以TiO₂作载体的HDS钼催化剂不仅活性和稳定性比MoO₃/Al₂O₃高,而且不经预硫化即可使用.但对MoO₃/TiO₂的表面结构的研究不多,对其表面酸性的报道就更少. 前已报道,用XRD,XPS,氨溶等对MoO₃/γ-Al₂O₃,MoO₃/SiO₂,MoO₃/TiO₂的研更多还原

【Abstract】 Two series of molybdenum trioxide-titanium dioxide samples(MoO3/ TiO2 and MoO3-TiO2)were prepared by different methods. The results of XRD, XPS and surface acidity investigation show that MoO3 is dispersed as a monolayer on TiO2 for both series, and their dispersion threshold values are the same. The curve of the density of acidic sites versus MoO3 content of the samples is consistent with that of XPS intensity ratio versus MoO3 content. The present results for MoO3/TiO2 are similar to that of MoO3/y-Al2O3 and MoO3/SiO2 systems, and further prove that the density of acidic sites depends on the surface concentration of MoO3. It is believed that the acidic oxide MoO3 dispersed on the surface of these carriers is the dominant origin of the acidity of the samples. This conclusion is quite different from that proposed in literatures.In addition, MoO3-TiO2 catalyst with large surface area can be obtained by using an appropriate preparation method. Its specific surface area can approach to that of the ordinary MoO3/r-Al2O3 catalyst.更多还原