Preparation And Application Of Ferrite Complex Oxides In Synthesis DMC

Dimethyl carbonate (DMC), a green chemical intermediate, has broad applicationprospects. DMC can be used as carbonyl and methylation reagent. CO2is rich and themain source of greenhouse on the planet. The environmental problems caused by CO2attract more attention. Direct synthesis of DMC from CO2and methanol is a promisingroute.The Fe2O3catalyst was prepared by precipitation method. The influence of differentpreparation conditions on the catalytic activity were studied. The DMC yield is1.52mmol/g over the catalyst prepared under optimal conditions, with the reactioncondition of catalyst1g, CH3OH500mmol, react temperature423K for24h. TG/DTA, IR,XRD and TEM were used to characterize catalysts. Fe2O3catalyst calcined by623K for2h achieves the highest DMC yield. Surface area of hematite is81.43m2/g, particlesdistribute from40nm to60nm.The effect of dehydrant on DMC yield was studied. The results show that DCC ismore effective than acetonitrile. When the amount of DCC is0.02mol, DMC yieldincrease5times than that of in absent of dehydrant. The effect of solvent on DMC yieldwas investigated. The results show that cyclohexane can improve the DMC yield. Whenthe cyclohexane and methanol ratio is2.6, DMC yield is1.5times of that without solvent.Toluene has no influence on the improve of DMC yield.The effect of doping different elements in Fe2O3on the DMC yield was studied. Fe-Ce catalyst shows a better catalytic activity. The preparation conditions of Fe-Ce catalystwere investigated. DMC yield is2.34mmol/g over the catalyst with the optimalpreparation conditions, and is1.5times of that over Fe2O3. BET, XRD and SEM-EDSwere used to characterize catalysts. The results show that the Fe-Ce-O solid solution isformed and the interaction between Fe and Ce. The interaction between Fe and Ce isuseful for activation of reactants.