Crystal structures, acid–base properties, and reactivities of CexZr1−xO2 catalysts

Direct synthesis of diethyl carbonate from ethanol and CO2 is attractive since starting materials are cheap and easily obtainable, and the initial operational procedures are quite simple. We present results showing that CexZr1−xO2 solid solution catalysts are effective and selective for producing diethyl carbonate and could be recyclable without loss of any activity. High calcination temperature is favorable based on results of catalytic test. X-ray diffraction and temperature-programmed desorption of NH3 and CO2 provide evidence indicating that catalytic properties of CexZr1−xO2 are closely dependent on the crystal structures and the acid–base sites on the surface with varied Ce/Zr ratios. Strong acid–base sites on the surfaces of catalysts are unfavorable for diethyl carbonate formation.