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本文用低能离子散射谱(ISS)研究MoO_3/γ-Al_2O_3催化剂的表面结构。ISS的I_(Mo)/I_(Al)与时间的关系即深度剖析曲线表明,MoO_3在γ-Al_2O_3上呈单层分散状态。样品顶层的MoO_3浓度与MoO_3总含量的关系表明,单层分散含量为MoO_3在γ-Al_2O_3上的几何单层量。焙烧温度增高时,~4He~+对顶层MoO_3的溅射速度显著变缓,说明通过焙烧,表面Mo—O—Al键有所强化,即活性组份与载体之间的相互作用加强。
In this paper, the surface structure of MoO_3 / γ-Al_2O_3 catalysts was investigated by low energy ion scattering spectroscopy (ISS). The relationship between I_ (Mo) / I_ (Al) of ISS and time, ie depth profile, shows that MoO_3 is monolayer dispersed on γ-Al_2O_3. The relationship between the concentration of MoO 3 and the total content of MoO 3 in the top layer of the sample shows that the monolayer dispersion content is the geometric monolayer content of MoO 3 on γ-Al 2 O 3. When the calcination temperature is increased, the sputtering speed of ~ 4He ~ + on the top MoO_3 is significantly slowed down, indicating that the surface Mo-O-Al bond is strengthened by the calcination, that is, the interaction between the active component and the support is strengthened.