摘要
文献对二元氧化物界面结构虽有介绍,但作者认为两者都是过渡金属氧化物时,在彼此表面能的作用下,表面各键都将扭曲,或脱离晶格分解成碎片,故很难说谁向谁分散,且分散也不一定是一个分子层.本文就MoO_3/ZrO_2(简写为Mo/Zr),MoO_3/V_2O_5(Mo/V)和MoO_3/WO_3(Mo/W)三体系进行了研究.
The dispersion capacities of ZrO2, V2O5 and MoO3 at the interface of MoO3/ZrO2 and MoO3/V2O5 calcined at 500℃ for 5h were studied by XRD and FT-IR difference spectra. The results show that there is a monolayer of the non-crystalline phase of V2O5 and ZrO2 at the interface, and 3 - 4 layers for MoO3. When MoO3 content is higher than the threshold value, the increment of non-crystalline phase of MoO3 is (1-0.77) and (1-0.73) times of the MoO3 content in MoO3/ZrO2 and MoO3/V2O5. For MoO3/WO3, the non-crystalline phases of WO3 and MoO3 are as monolayer and 3-4 layers respectively, when the content of both oxides exceeds the threshold value, the increment of non-crystalline phase is (1-0.78) and (1-0.54) times respectively. The selectivity of MoO3/ZrO2 ,MoO3/V2O5 and MoO3/WO3 for o-xylene oxidation is closely related to the surface amorphous Mo-O-Zr, Mo-O-V and Mo-O-W,
基金
国家自然科学基金
