Synthesis of glycerol carbonate and monoacetin from glycerol and carbon dioxide over Cu catalysts: the role of supports

Abstract BACKGROUND Glycerol is a co‐product in biodiesel production, and glycerol carbonate is an important product from the carbonylation of glycerol. However, the direct reaction of glycerol with CO 2 is limited by thermodynamics. Cu‐based catalysts were applied in the synthesis of glycerol carbonate and monoacetin from glycerol and CO 2 in the presence of CH 3 CN to overcome the thermodynamic limitation. RESULTS The physical and chemical properties of Cu‐based catalysts supported on different supports were characterized by XRD , BET , TEM , NH 3 / CO 2 ‐TPD , H 2 ‐TPR and N 2 O chemisorptions. The supported Cu catalysts exhibited different sizes of Cu particles and different acid–base properties. The reaction routes could be divided into three steps: the carbonylation of glycerol with CO 2 , the hydrolysis of CH 3 CN and the esterification of glycerol with acetic acid. The esterification of glycerol with acetic acid was more preferable thermodynamically to promote the whole reaction. CONCLUSION Cu species played the decisive role in the activity of the catalysts in this reaction. The reaction rate of glycerol decreased with the increase of Cu particle size. The catalysts with Lewis base sites tended to favor the formation of glycerol carbonate, and the Lewis acid sites accelerated the formation of monoacetin. © 2014 Society of Chemical Industry