BACKGROUND: Ethylene carbonate (EC) was synthesised via urea and ethylene glycol (EG) over zinc/iron catalyst. By so doing, the by-product, EG, generated in the process of producing dimethyl carbonate by the transesterification route was converted back to the raw material, EC. The reaction mechanism of EC synthesis was also investigated by means of gas chromatography/mass spectrometry and in situ Fourier transform infrared/attenuated total reflection spectroscopy. RESULTS: Suitable conditions for the preparation of zinc/iron oxide catalyst were as follows: zinc acetate and iron nitrate as precursors, Zn/Fe molar ratio 8 1 :1, calcination temperature 350 degrees C and calcination time 4h. Characterisation by X-ray diffraction revealed two different crystal phases: ZnO and ZnFe2O4. The highest yield of EC (66.1%) was obtained under the following conditions: reaction temperature 150 degrees C, reaction time 2.5h, catalyst weight percentage 1.5% and urea/EG molar ratio 1:8. The study of the reaction mechanism revealed that the reaction for the synthesis of EC proceeded in two steps. CONCLUSION: The synergistic effect of ZnO and ZnFe2O4 promoted the catalytic performance of zinc/iron oxide. (c) 2008 Society of Chemical Industry.