Synthesis of glycerol carbonate from glycerol and dimethyl carbonate using magnesium–lanthanum mixed oxide catalyst

Various magnesium–lanthanum mixed oxide catalysts having different Mg/La molar ratio were prepared and their catalytic activities for the transesterification of dimethyl carbonate (DMC) with glycerol for the synthesis of glycerol carbonate (GLC) were compared. Depending on the molar ratio of Mg/La, the precipitation agent, and the calcinations temperature in the preparation step, the catalytic activity and the surface basic site concentration changed. The most active catalyst having the high basic site concentration was obtained when a 3/1 molar ratio of Mg(NO3)2·6H2O/La(NO3)3·6H2O mixture was co-precipitated using a KOH/K2CO3 mixture and calcined at 720 °C for 4 h. Catalyst characterization using XRD, elemental analysis, Brunauer–Emmet–Teller (BET) surface area, and TPD revealed that the catalyst preparation condition affected catalyst composition, structure, and surface area as well as basic site concentration. The effect of reaction conditions such as reaction time, DMC/glycerol molar ratio, reaction temperature, and catalyst amount were also discussed.

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► Mg–La mixed oxides showed higher catalytic activity compared to MgO and La2O3 single metal oxide catalysts.
► Mg3La1 showed the highest catalytic activity among Mg–La mixed oxides.
► Catalytic activity of Mg–La oxides is affected by Mg/La ratio, precipitating agent, and calcination temperature.