【摘要】 MoO₃与不同制备方法和来源的γ-Al₂O₃（包括η-Al₂O₃）干混、焙烧制备的样品,或者用浸渍、焙烧制备的样品,通过X光衍射测得的MoO₃最大分散量都与按密置单层模型计算得到的结果(每100米²γ-Al₂O₃表面0.117克MoO₃,即4.9×10¹⁸Mo原子/米²)相近。这样可以通过X光衍射测定MoO₃在每克γ-Al₂O₃上的最大分散量而得到γ-Al₂O₃的比表面。比表面和孔容的研究结果也支持MoO₃在γ-Al₂O₃表面呈密置单层分散的模型。更多还原

【Abstract】 The monolayer dispersion capacities of MoO3 on γ-Al2O3 (or η A12O3) of different kinds with different specific surface, which were made from boehmite,bayerite and gibbsite, calcined at different temperatures were determined by XRD and specific surface measurement. Their values are nearly the same (around 0.12-0.13 g MoO3/100 m2 surface of γ-Al2O3) and close to 0.117 g MoO3/100m2 surface of r-A12Q3 calculated from a close-packed monolayer model (see Fig. 1-3 and Table 1). Samples of MoO3/Al2O3 prepared by impregnation method or by heating the mixture of MoO3 and A12O3 gave the similar results (see Fig. 4, 5). The specific surface and pore volumes of MoO3/γ-Al2O3 systems determined also support the close-packed monolayer model, because the specific surfaces or pore volumes per gram r-Al2O3 keep on almost no change as the amounts of MoO3 in MoO3/γ-Al2O3 samples exceed the monolayer dispersion capacity (see Fig. 6-8). It is suggested that the specific surface of γ-Al2O3 (or Al2O3) can be obtained from the XRD determination of the monolayer dispersion capacity of MoO3 on the γ-Al2O3 (or η-A12O3).更多还原