研究了不同载量时Mg(NO3)2在γ-Al2O3上存在状态和热分解行为差异.考察了Mg含量不同时MgO/γ-Al2O3的碱性变化情况，并与水滑石焙烧产物Mg(Al)O的碱性进行了对比.结果表明,Mg(NO3)2可单层分散于γ-Al2O3表面，Mg(NO3)2的分散决定了MgO的分散阈值；单层态的Mg(NO3)2比晶态的分解温度低；MgO/γ-Al2O3在阈值附近具有单位表面最高碱量，碱位分布与Mg(Al)O相似，单位表面碱量高于Mg(Al)O.由于γ-Al2O3的织构可以方便地调节，且MgO/γ-Al2O3很容易制备，MgO/γ-Al2O3是一个很有应用前景的固体碱.%The state and thermal decomposition behavior of Mg(NO3)2 on γ-Al2O3 at different Mg loading were studied by XRD and TG-DTA. The basicity of MgO/γ-Al2O3 with different Mg loading was investigated by CO2-TPD and compared with that of Mg-Al mixed oxides derived from hydrotalcite. Results show that Mg(NO3)2 can disperse on γ-Al2O3 as a monolayer and its dispersion determines the dispersion threshold of MgO on γ-Al2O3. Mg(NO3)2 in dispersion state has lower decomposition temperature than that in crystal state. The amount of basic sites per square meter on the surface of MgO/γ-Al2O3 shows a highest value around the loading of threshold, which indicates that the basicity of MgO/γ-Al2O3 originates from MgO in dispersion state. The basicity of MgO/γ-Al2O3 around the threshold loading is comparable and even superior to that of Mg(Al)O derived from hydrotalcite. Since the texture and specific area of γ-Al2O3 can be easily adapted and there are various kinds of commercial γ-Al2O3 available, MgO/γ-Al2O3 is a promising solid base that may be found in use.
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