【作者】 陈杰；

【导师】 张渊明；

【作者基本信息】 暨南大学 ， 物理化学， 2015， 硕士

【摘要】 生物柴油具有和石化柴油相似的理化性质,且生物柴油可循环利用、可降解、无毒等特性使其成为替代石化柴油的最佳选择。而在生物柴油的产业过程中,产生了大量的副产物——甘油。为了保持甘油原有市场的平衡,提高甘油的附加值,促进生物柴油产业的发展,开发高附加值的甘油衍生物已成为研究的重点。碳酸甘油酯是最有吸引力的衍生物之一,本文将沉淀法制备的纯相La2O2CO3催化剂和浸渍法制备的Ni Cu负载的Ni Cu/La2O2CO3催化剂用于催化甘油和尿素转化为碳酸甘油酯,取得较高活性。采用X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、BET比表面积、X射线光电子能谱(XPS)、程序升温脱附(TPD)等手段对催化剂的结构进行表征,优化了合成碳酸甘油酯反应的最佳条件,初步研究了催化剂的结构与性能之间的构效关系。沉淀法制备的纯相La2O2CO3催化剂的催化结果表明:在反应温度145℃,甘油与尿素的摩尔比为1:1,反应时间1 h,催化剂用量为3%(以甘油质量计)时,甘油的转化率最高为83.69%,碳酸甘油酯的选择性最高为83.74%,与商品的La2O3催化剂相比,具备较高的碳酸甘油酯收率。该催化剂在合成碳酸甘油酯的反应中,转化频率(TOF)为304mmol/g·h。为了进一步提高催化剂的催化活性,使用浸渍法制备了Ni Cu负载的Ni Cu/La2O2CO3催化剂。当负载量为10%,反应温度145℃,反应时间1 h,甘油与尿素摩尔比为1:1,催化剂用量为0.67%,甘油的转化率最高为79.73%,碳酸甘油酯的选择性最高为79.75%。Ni Cu(10)/La2O2CO3催化剂在合成碳酸甘油酯反应中的TOF高达2547 mmol/g·h,活性较改性前增长了7倍多。TPD分析结果显示,改性后催化剂的高强度碱性位(Td>400℃)的增加是催化活性增加的主要原因。本研究成功制备了用于催化甘油合成碳酸甘油酯的催化剂,该催化剂展现出较好的催化活性以及稳定性,对于甘油的催化转化具有重要的指导作用。更多还原

【Abstract】 Biodiesel has similar physical and chemical properties with petrochemical diesel. Biodiesel can be recycle used, biodegradable, non-toxic and its these excellent features make it become the best choice to replace petroleum diesel. While during the process of biodiesel industry, glycerol produced a lot as a byproduct. In order to maintain the balance of the glycerol existing market, improve the added value of glycerol and promote the development of biodiesel industry, many researchers focus on the study of value-added glycerol derivatives. And glycerol carbonate is one of the most attractive glycerol derivatives. In this study, pure La2O2CO3 catalyst and Ni, Cu supported Ni Cu/La2O2CO3 catalysts were prepared via precipitation method and impregnation method, respectively. They were used in the synthesis of glycerol carbonate from glycerol and urea, and the catalysts showed good performance. The structure properties of the as-prepared catalysts were studied by X-ray diffraction(XRD), Scanning electron microscope(SEM), transmission electron microscopy(TEM), Brunauer, Emmett and Teller method analyses(BET), X-ray photoelectron spectroscopy(XPS), temperature programmed desorption(TPD) and so on. The optimum reaction conditions for synthesis of glycerol carbonate were studied as well. The structure-activity relationship was investigated preliminarily.The catalysis results of pure La2O2CO3 catalyst prepared via precipitation method showed that: when the reaction temperature was 145 ?C, the ratio of glycerol to urea was 1:1, the reaction time was 1 h, catalyst loading was 3%(respect to glycerol), the conversion of glycerol was 83.69% with 83.74% selectivity to glycerol carbonate. The turnover frequency(TOF) of the catalyst in this reaction was 304 mmol/g·h. It gives high catalytic activity.Ni, Cu supported Ni Cu/La2O2CO3 catalyst was prepared through impregnation method to improve the catalytic activity of the La-based catalyst. When the loading of Cu and Ni was 10%, the reaction conditions were the same as the above, except the catalyst loading. The dosage of supported Ni Cu/La2O2CO3 was 0.67%(respect to glycerol), and the conversion of glycerol was 79.73%, the selectivity to glycerol carbonate was 79.75%. Ni Cu(10)/La2O2CO3’s TOF in the synthesis of glycerol carbonate is as much as 2547 mmol/g·h, which increased by more than 7 times.In this study, catalysts used in the synthesis of glycerol carbonate were successfully prepared. The catalysts exhibited good catalytic activity and stability and there is an important guidance for the catalytic conversion of glycerol.更多还原