Transesterification of dimethyl carbonate with diethyl carbonate over Al-Zn-MCM-41 and Al-MCM-41 molecular sieves

Al-MCM-41 (Si/Al = 50, 100) and Al-Zn-MCM-41 (Si/Al + Zn = 50, 100) were synthesised hydrothermally and characterised by XRD, BET, TPD-Pyridine, FT-IR and 27Al MAS-NMR techniques. Their catalytic activity was tested for the transesterification of dimethyl carbonate (DMC) with diethyl carbonate (DEC). The reaction was carried out at 125, 150, 175 and 200 °C with feed ratio 1:1. Al-Zn-MCM-41 (50) was found to be more active than other catalysts. The DMC conversion was maximum at 175 °C. The study of time-on-stream showed decrease of conversion with increase in stream. The activity of the catalysts followed the order Al-Zn-MCM-41 (50) > Al-Zn-MCM-41 (100) > Al-MCM-41 (50) > Al-MCM-41 (100), which is also the order of the acidity of the catalysts.