Mg-Al-O复合氧化物催化剂的表面酸碱性质(Ⅱ):酸碱种类研究

Surface acidity and basicity of Mg-Al-O mixed oxide catalyst(Ⅱ): stuty of the nature for acid and base sites

:分别在 673、873和 10 73K分解Mg/Al物质的量比为 3的水滑石生成Mg -Al -O复合氧化物。用NH3和CO2 作探针分子 ,采用红外光谱 ,真空原位测定样品表面酸碱中心的种类 ,主要存在L酸 ,而碱中心是氧阴离子。结果表明 。

Magnesium-Aluminum mixed oxides obtained from hydrotalcite compounds upon calcination at 673,873and1073K,respectively. NH 3andCO 2 molecules were used as the probing molecules to investigate the nature of acid and base sites on Magnesium-Aluminium mixed oxides. Infrared spectroscopic studies of these adsorped molecules indicated that the acid sites were mainly Lewis acid sites, whereas the base sites were surface oxygen anions. The results showed that the calcination temperature few influences on the nature of surface base sites.