Direct synthesis of dimethyl carbonate over rare earth oxide supported catalyst

Abstract

Solid base catalysts for the direct synthesis of dimethyl carbonate (DMC) from carbon dioxide, methanol, and propylene oxide were prepared by loading KCl and K₂CO₃ on the surface of La₂O₃, Y₂O₃, CeO₂ and Nd₂O₃. The catalysts were characterized by thermogravimetric analysis (TGA) and X-ray diffraction (XRD) techniques. The catalytic activities were efficiently influenced by the preparation conditions. The optimal loading amount of K₂CO₃ is 17.6% (mass) for KCl-K₂CO₃/Y₂O₃ and 22.2% for other catalysts. Supports affected the activity of catalyst. KCl-K₂CO₃/Nd₂O₃ exhibited the highest activity. The activity of KCl-K₂CO₃/Y₂O₃ increased with the increase of calcination temperature in the range of 800ºC–900ºC. The formation of KYO₂, Y₃O₄Cl or YO_X species probably promoted the catalysts.