The Research Of Diethyl Carbonate From Carbon Dioxide-ethanol Over Zirconium Oxide/Molecular Sieve Catalysts

CO2chemistry is the most cheap and abundant carbon resources in the C1family. Itsimmobilized and utilization research is one of the most important subjects to all countries inthe world. The research on synthesis of diethyl carbonate (DEC) from carbon dioxide can gethigh value-added chemical products. It also can make an important improvement to theecological environment. In this paper, direct synthesis of diethyl carbonate by Zirconium (IV)oxide (ZrO2) and molecular sieves from carbon dioxide and ethanol was studied, and thereaction conditions were optimized.ZrO2/3A molecular sieve had a high catalytic activity in the synthesis of diethyl carbonatefrom CO2and ethanol.When3A molecular sieve was added into the reaction as a co-catalyst,the yield of DEC was effectively improved about1-fold. The preparation methods of catalystswere also optimized. The zirconium oxide was obtained by the precipitation method in thepH9and calcined at600℃. Then ZrO2and3A molecular sieves were mixed as the mass ratioof5:2. In addition, the ZrO2and3A molecular sieves were also characterized.The optimized conditions were obtained as follows, reaction temperature150℃, reactionpressure7Mpa, reaction time2h. When CO2and ethanol were charged with molar ratio of514/225mmol, the yield of DEC could reach0.0543mmol with the selectivity of60%.In this catalytic system, adding the dehydrating agent, such as ethylene, acetonitrile,propylene oxide and epoxybutane, into the reaction can not efficiently improve the reactionyield.