Acid–Base Synergistic Catalysis Over Zn/ Al Layered Double Oxides Toward the Hydrolysis of Ethyl Carbonate Under Mild Conditions

Among many ethylene glycol synthetic methods, the ethylene carbonate route is preferred due to its extremely high EG selectivity and low EC/ H2O ratio. In this work, we synthesized a variety of layered double hydroxides (LDH) and layered double oxides (LDO) by co–precipitation method for the hydrolysis of EC. The Zn3Al–LDO showed the highest catalytic activity under low EC/ H2O ratio and mild conditions, and the EG yield of 93%–99% could be obtained at 100 °C for 3–4 h. It was found that Zn3Al–LDO has larger pore diameter and pore volume than Zn2Al–LDO and Zn4Al–LDO. It could retain a host of base sites in the hydrolysis system because it had no "memory effect". The active sites inhibition experiment proved that Zn3Al–LDO is an acid–base synergistic catalyst and the base sites are dominant. The catalyst can be recycled at least five times with calcination and activation to maintain excellent catalytic activity.