Synthesis, characterization and catalytic behavior of a zinc acetate complex immobilized on silica-gel
Synthesis, characterization and catalytic behavior of a zinc acetate complex immobilized on silica-gel
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DOI：
10.1016/s0926-860x(02)00072-8
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发表时间：
2002-05
影响因子：
5.5
通讯作者：
R. Nava;T. Halachev;R. Rodríguez;V. Castaño
中科院分区：
文献类型：
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作者：
R. Nava;T. Halachev;R. Rodríguez;V. Castaño
采用溶胶-凝胶法制备了一种新型的硅胶-琥珀酸-醋酸锌杂化材料。以前用琥珀酸（SA）处理硅溶胶，目的是使其表面功能化。在酸和表面硅烷醇基团之间观察到一种不确定的键合模式。醋酸锌（ZnA）通过游离SA羟基与ZnA配合物之间的不确定键连接而固定在处理后的硅溶胶表面。采用SBET、XRD、FT-IR和热分析对样品进行了表征。在工业上重要的对苯二甲酸二甲酯（DMT）和乙二醇（EG）酯化反应中测试了样品的催化活性。观察到的非均相催化剂的催化活性与均相ZnA催化剂的催化活性几乎相等。该催化剂可在不同的催化循环中重复利用。
The development of a novel hybrid silica-gel–‘succinic acid–zinc acetate’ material, prepared by the sol–gel method, is presented in this work. Silica sol was previously treated with succinic acid (SA) with the aim to functionalize its surface. A unidentate bonding mode is observed between the acid and the surface silanol groups. The immobilization of the zinc acetate (ZnA) on the treated silica sol surface was accomplished via unidentate bonding between the free SA hydroxyl group and the ZnA complex. The samples were characterized by SBET, XRD, FT-IR and thermal analysis. The catalytic activity of the samples was tested in the industrially important reaction of esterification of dimethyl terephthalate (DMT) and ethylene glycol (EG). The observed catalytic activity of the heterogeneous catalyst is practically equal to that of the homogeneous ZnA catalyst. The catalyst can be reutilized during various catalytic cycles.