钙铈基催化剂上碳酸丙烯酯和甲醇制备碳酸二甲酯的研究

Investigation on production of dimethyl carbonate from propylene carbonate and methanol on calcium cerium-based catalysts

摘要: 采用溶胶凝胶法制备了不同比例的钙铈基催化剂，并研究了其对于碳酸丙烯酯和甲醇制备碳酸二甲酯的酯交换反应性能。结果表明， Ca∶Ce=9的催化剂在反应时间2 h，温度40 ℃，甲醇与碳酸丙烯酯物质的量比为15∶1，催化剂用量为碳酸丙烯酯用量4%的条件下，碳酸丙烯酯转化率达到91.1%，碳酸二甲酯选择性达到91.7%。采用XRD、N₂吸附-脱附、FT-IR、XPS和CO₂-TPD对催化剂进行了表征。结果表明，催化剂表面的氧空穴越多，中等碱性位数量越多，越有利于甲醇的活化，催化剂的活性越好。

Abstract: Calcium cerium-based catalysts with different Ca:Ce molar ratio prepared by sol-gel method were characterized by XRD, N₂ adsorption-desorption, FT-IR, XPS and CO₂-TPD, and evaluated the activity for dimethyl carbonate (DMC) synthesis from propylene carbonate (PC) and methanol. The results indicated that more surface oxygen vacancies and more moderate basic sites are beneficial for methanol activation and thus leading to better catalytic activity. The PC conversion was 91.1% with DMC selectivity of 91.72% over 0.9CaCe under the reaction conditions-reaction time of 2 h, reaction temperature of 40 °C, methanol to propylene carbonate molar ratio of 15:1 and catalyst amount of 4% relative to the amount of PC.