合成三氧化二鈰氣凝膠應用於乙醇/碳酸乙烯酯轉酯化反應之應用

Synthesis of Ce2O3 Aerogels for Ethanol/Ethylene Carbonate Transesterification Reaction

梁智鈞(Chin-Chun Liang)

指導教授 ： 林義峯

中原大學/工學院/化學工程研究所/碩士(2019年)

https://doi.org/10.6840/cycu201900696

摘要

本研究成功利用分散無機溶膠凝膠法，選用硝酸鈰溶於溶劑乙醇，並加入螯合劑檸檬酸以及凝膠化起始劑環氧丙烷製備出三氧化二鈰氣凝膠。接著使用3-胺丙基三甲氧基矽烷將氣凝膠表面進行氨基改質形成氨基改質之三氧化二鈰氣凝膠。將此觸媒應用於碳酸乙烯酯與乙醇的轉酯化反應生成綠色化學品碳酸二乙酯。碳酸酯類轉酯化反應需要大量的路易斯鹼活性位點去催化反應的進行，氧化鈰為一種鹼性金屬氧化物，富含大量的路易斯鹼活性位點，將其製備成金屬氧化物氣凝膠能夠增加其比表面積提升催化活性。接著再利用氣凝膠易改質的優點，將觸媒進行氨基改質增加觸媒的路易斯鹼活性位點，達成更高的催化效果。
本研究接著探討不同金屬前驅物與螯合劑比、改質劑濃度、改質次數、反應溫度、反應時間、反應醇酯比以及觸媒量對於催化效果的探討。再找到最佳的參數之後，可以得到79.26 %的碳酸二乙酯產率，證實其為一種相當具有潛力之材料。

關鍵字

金屬氧化物氣凝膠 ； 分散無機溶膠凝膠法 ； 氧化鈰 ； 轉酯化反應 ； 碳酸乙烯酯 ； 碳酸二乙酯 ； 乙醇

並列摘要

In this study, a dispersed inorganic sol-gel method was successfully used to prepare a cerium (III) oxide aerogel by dissolving cerium nitrate in solvent ethanol, adding a chelating agent citric acid and a gelation initiator propylene oxide. Further, the surface of the aerogel was modified by amino using 3-aminopropyltrimethoxydecane to form an amino-modified cerium (III) oxide aerogel. The catalyst is applied to the transesterification reaction of ethylene carbonate with ethanol to form a green chemical diethyl carbonate. The carbonate transesterification reaction requires many Lewis base active sites to increase the catalytic reaction. The cerium oxide is a basic metal oxide, full of Lewis base active sites. And the preparation of the metal oxide aerogel can increase its specific surface area to enhance the catalytic activity. Then, using the advantages of aerogel that easy to modify, the amino modification of the catalyst increases the Lewis base active sites of the catalyst to achieve a higher catalytic effect.
The study then explored the ratio of different metal precursors to chelating agents, modification concentration, number of times of modification, reaction temperature, reaction time, reaction alcohol-ester ratio and amount of catalyst for the catalytic effect. After finding the best parameters, a yield of 79.26% of diethyl carbonate was obtained, which proved to be a relatively promising material.

並列關鍵字

Metal oxide aerogel ； Dispersed inorganic sol-gel method ； Cerium oxide ； Transesterification ； Ethylene carbonate ； Diethyl carbonate ； Ethanol

參考文獻

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