Synthesis, characterization and catalytic behavior of a zinc acetate complex immobilized on silica-gel Original Research Article

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.