【摘要】 通过化学还原法和共沉淀法分别制备了非晶态和晶态的FeCeO_x/SiO₂固体碱催化剂。与晶态的FeCeO_x/SiO₂相比,非晶态的FeCeO_x/SiO₂催化剂对梨醇酯与甲醇的酯交换活性显著提高。通过电感耦合等离子体质谱（ICP-MS）、N₂吸附-脱附、透射电子显微镜（TEM）结合选区电子衍射（SAED）、X射线衍射（XRD）、X射线光电子能谱（XPS）、CO₂-TPD和NH₃-TPD等对催化剂进行表征。结果表明催化剂的活性与其碱性密切相关,非晶态FeCeO_x/SiO₂显示出相对于晶态FeCeO_x/SiO₂更强的碱性。使用非晶态FeCeO_x/SiO₂催化剂进行梨醇酯酯交换反应,在130℃下反应10 h,梨醇酯的转化率达到95%,异戊烯醇的选择性达到96%。在重复使用10次后,催化剂活性基本不变。对新鲜的和套用10次后的FeCeO_x/SiO₂催化剂进行X射线衍射分析,表明该催化剂在套用10次后仍未晶化,证实其具有良好的稳定性,说明该催化剂在非均相催化酯交换反应中具有应用价值。更多还原

【Abstract】 Both amorphous and crystalline FeCeO_x/SiO₂ solid base catalysts were prepared by chemical reduction and co-precipitation methods, respectively. The activity of amorphous FeCeO_x/SiO₂ for the transesterification of prenyl acetate with methanol was remarkably enhanced compared with crystalline FeCeO_x/SiO₂. The catalysts were characterized by inductively coupled plasma mass spectrometry（ICP-MS）, N₂ adsorption-desorption,transmission electron microscopy（TEM） in combination with selected area electron diffraction（SAED）, X-ray diffraction（XRD）, X-ray photoelectron spectroscopy（XPS）, and temperature programmed desorption（CO₂-TPD and NH₃-TPD）. As a result, the activity of the catalysts is found to be closely related to its basicity, and the amorphous FeCeO_x/SiO₂ shows higher basicity. Prenyl acetate conversion of 95% and prenyl alcohol selectivity of 96% were obtained using amorphous FeCeO_x/SiO₂ catalyst in transesterification reaction at 130 ℃ for 10 h. The catalyst maintained a high level of activity after 10 cycles of testing. X-ray diffraction analyses of fresh and used FeCeO_x/SiO₂ catalyst demonstrated that this catalyst is exceptionally stable, which could be of value in industrial application related to heterogeneous catalytic transesterification.更多还原