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V_2O_5—MoO_3体系是重要的氧化催化剂体系之一.许多作者分别用X射线衍射对V_2O_5—MoO_3体系进行了物相分析,测定了有关的晶体结构,用热分析或熔点显微镜研究其相图等.据文献报道,V_2O_5—MoO_3体系中当MoO_3含量低于约40mol％时,可形成MoO_3在V_2O_5中的固溶体相;当 MoO_3含量在约50mol％或稍高时,可形成中间化合物相;当MoO_3含量更高时,则以MoO_3相为主.但是,文献中对于V—Mo—O中间化合物相的化学组成的认识存在着分岐,有些作者归结为V_2MoO_8,另一些作者则归结为V_9Mo_6O_(40).这两种分子式表示法的差异首先在于V和Mo的原子比不
V_2O_5-MoO_3 system is one of the important oxidation catalyst systems.Many authors have carried out the phase analysis of the V_2O_5-MoO_3 system by X-ray diffraction, determined the relevant crystal structure, and studied the phase diagram by thermal analysis or melting point microscope. It has been reported in the literature that the solid solution phase of MoO_3 in V_2O_5 can be formed when the MoO_3 content is less than about 40 mol% in the V_2O_5-MoO_3 system. When the MoO_3 content is about 50 mol% or higher, an intermediate compound phase can be formed. When the MoO_3 content Higher, MoO_3 phase is dominant, however, there is a disagreement in the literature about the chemical composition of the V-Mo-O intermediate compound phase, some authors attribute to V_2MoO_8 and others to V_9Mo_6O_ (40). The difference between the two formulas is above all the atomic ratio of V to Mo