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应用XRD及BET方法研究了MoO3-Fe2O3,MoO3-V2O5,MoO3-TiO2(锐钛矿),MoO3-WO3和MoO3-ZrO2五种二元过渡金属氧化物界面上的相互作用及非晶相自发分散。这些二元氧化物均含有0~100%之间的十个不同掺杂配比的MoO3,经干混和适宜温度下焙烧而得。XRD晶相定量分析及外推法证明,每种组分氧化物都在界面上自发分散为非晶相,并具有各自的分散阈值。当配比大于分散阈值时,各组分氧化物焙烧后的剩余晶相量与加入晶相量之间为线性关系,其中MoO3和ZrO3的斜率显著小于1。BET测定证明,所有试样的比表面积(3.71~11.25m2/g)较常见载体如SiO2等小得多。MoO3在五种二元氧化物界面的分散阈值各不相同(0.33~1.43g/100m2),远大于唐有祺等人根据O2-密置模型计算得的在高比表面载体上的单层饱和容量(0.117g/100m2)。这预示着界面上可能存在非单层分散及表面化学反应,XRD晶相分析及后续文章中FT-IR等表征手段证实了此点。
The interfacial interactions and the spontaneous dispersion of amorphous phase at five binary transition metal oxides such as MoO3-Fe2O3, MoO3-V2O5, MoO3-TiO2 (anatase), MoO3-WO3 and MoO3-ZrO2 were investigated by XRD and BET methods. . These binary oxides contain 0 to 100% of the ten different doping ratio of MoO3, obtained by dry mixing and roasting at a suitable temperature. XRD crystalline phase quantitative analysis and extrapolation proved that each component of oxide spontaneous dispersion at the interface as an amorphous phase, and have their own dispersion threshold. When the ratio is greater than the dispersion threshold, the amount of residual crystalline phase after calcination of each component oxide is linear with the amount of added crystalline phase, with the slopes of MoO3 and ZrO3 being significantly less than one. The BET measurement proves that the specific surface area (3.71 ~ 11.25m2 / g) of all samples is much smaller than that of common carriers such as SiO2. The dispersion thresholds of MoO3 at five binary oxide interfaces vary from 0.33 to 1.43 g / 100 m2, which is much larger than the monolayer saturation capacity of high surface area carriers calculated by Tang Youqi et al. 0.117 g / 100 m2). This indicates that there may be non-monolayer dispersion and surface chemical reaction at the interface, which is confirmed by the XRD crystal phase analysis and subsequent characterization by FT-IR.