负载型MoO3催化剂结构与催化酯化性能研究

Study on Structure and Catalytic Performance of Supported MoO3 Catalyst in Esterification

摘要:

以SiO2和Al2O3为载体，采用等体积浸渍法制备了MoO3质量分数为1 -30 wt%的负载型MoO3催化剂。采用X射线粉末衍射（XRD）、比表面积测定（BET）、程序升温脱附（NH3-TPD）等对催化剂的结构和性能进行了表征，以乙酸乙酯的合成为模型反应评价了催化剂的催化酯化性能。结果表明，MoO3/SiO2和MoO3/Al2O3催化剂对酯化反应具有较好的催化活性和选择性，对于MoO3/SiO2催化剂，适宜的MoO3负载量为5 wt%。催化剂的多孔结构和弱酸中心有利于酯化反应的进行。

Abstract:

A series of supported MoO3 catalysts were prepared by an equivalent-volumetic impregnation method with MoO3 loadings ranging from 1 to 30 wt%, with SiO2 and Al2O3 as the carrier. The samples were characterized by X-ray diffraction (XRD), specific surface area measurements (BET), temperature-programmed desorption (NH3-TPD). The catalytic esterification of acetic acid with ethanol was carried out in a three-neck flask at 90-100℃.The results clearly revealed that MoO3/SiO2 and MoO3/Al2O3 catalysts were active and selective towards the formation of ethyl acetate. The MoO3/SiO2 catalyst containing 5 wt% MoO3 was the most active and selective one. The results emphasize the importance of the porous structure together with the weak acidic sites of the prepared catalyst towards ester formation.