含官能基介孔二氧化矽材料的製備與其應用於生質能源之研究

Abstract

本論文中，第一部份是針對長碳鏈三酸甘油酯的鹼催化轉酯化之研究。首先，分別成功地合成出含胺、胍與咪唑的丙基矽氧烷，並以EO20PO70EO20作為模板試劑，四乙氧基矽烷當作矽源，以一鍋共沉澱法合成出一系列扁平狀與棒狀的仿生鹼SBA-15。並藉由三乙酸甘油酯與甲醇的反應，成功證實了胺─咪唑與胍─咪唑有協同反應的現象，而此現象能大幅度提升仿生鹼觸媒的催化活性。且在無水條件下，該觸媒能做多次的再生與使用。最後，此觸媒亦確實能迅速地催化長碳鏈的三棕櫚酸甘油酯與甲醇與轉酯化反應。 第二部份是長碳鏈脂肪酸的酸催化酯化之研究。首先，成功合成出含酚基的丙基矽氧烷，並以EO20PO70EO20作為模板試劑，四乙氧基矽烷當作矽源，以一鍋共沉澱法合成出含酚基扁平狀的SBA-15。最後再以發煙硫酸磺酸化，得到含酚磺酸之扁平狀SBA-15。由棕櫚酸與甲醇或異丙醇的酯化測試反應，該觸媒比含丙基磺酸之扁平狀SBA-15與商用Amberlyst-15 resin的活性來的好，且能以簡易的再生方式重複催化3次，並保有良好的活性。 第三部份是縮醛與醚類催化水解之研究。首先，成功合成出含硫親核基的丙基矽氧烷，並以EO20PO70EO20作為模板試劑，四乙氧基矽烷當作矽源，以一鍋共沉澱法合成出含硫親核基扁平狀的SBA-15。最後再以發煙硫酸磺酸化，得到含芳香性磺酸-硫親核基之雙功能扁平狀SBA-15。首先，由棕櫚酸與甲醇的酯化測試反應，該觸媒比含丙基磺酸之扁平狀SBA-15與商用Amberlyst-15 resin的活性來的好，且能以簡易的再生方式重複催化4次，並保有良好的活性。藉由1,4-二噁烷的水解反應，成功證實了硫─磺酸有協同反應的現象，而此現象能大幅度提升觸媒的催化水解活性。而此觸媒在水解較為疏水的苯甲醚上，亦有不錯的轉化率。最後，此觸媒亦確實能水解纖維素並形成小分子有機酸與癸烷。

Bio-fuel, including biodiesel and bio-ethanol, are considered to be a sustainable energy against the increasing of fuel shortages. In the first part, inspired form biomimicry, mesoporous biomimetic base-functionalized platelet silica materials were prepared. Two biomimic silanes, 3-guanidinyl- propyltrimethoxysilane （GuTMS） and 3-imidazolyl- propyltrimethoxysilane （ImTMS）, were synthesized. The functionalized mesoporous silica material （briefly termed Gu-Im-SBA-15-p） was prepared by co-condensation of GuTMS, ImTMS and TEOS in the presence of P123 as pore directing agent, following the procedure of platelet SBA-15 synthesis. Functionalized with “catalytic triad”, the domain discovered in chymotrypsin and used to hydrolyze peptides, Gu-Im-p, platelet SBA-15 demonstrated the synergistic effect between the imidiazole and guanidine groups and gave higher activity than the singly functionalized materials in catalyzing the transesterification, It was an efficient catalyst for biodiesel synthesis through the transesterification of triacetin or tripalmitin with methanol. In the next study, mesoporous platelet silica materials functionalized with aryl sulfonic acid were prepared. 3-(2-hydroxy-5-methylphenyl)- propyltrimethoxysilane （PholTMS） was synthesized first. Then, functionalized mesoporous silica material （briefly termed PholSO3H-SBA-15-p） was prepared by co-condensation of PholTMS and TEOS in the presence of P123 as pore directing agent, following the procedure of platelet SBA-15 synthesis. After removal of the P123 template the functionalized SBA-15 underwent sulfonation with sulfuric acid and oleum. The resultant material was found to be efficient catalyst for biodiesel synthesis through the esterification of palmitic acid with methanol or isopropanol. In comparison to the commercial Amberlyst-15 resin, PholSO3H-SBA-15-p showed higher catalytic activity in the esterification reaction. The catalytic activity of the material was retained after recycling for 3 times through simple regeneration by filtration and drying at 373 K. In the final part, mesoporous platelet silica materials functionalized with thio-aryl sulfonic acid were prepared. 3-thiophenyl- propyltrimethoxysilane （ThioTMS）was first synthesized. The functionalized mesoporous silica material （briefly termed ThioSO3H-SBA-15-p）was prepared by co-condensation of ThioTMS and TEOS in the presence of P123 as pore directing agent, following the procedure of platelet SBA-15 synthesis. After removal of P123 template by extraction the functionalized SBA-15 underwent sulfonation with sulfuric acid and oleum. Functionalized with strong sulfur-type nucleophilic group, the resultant material was found to be efficient catalyst for biodiesel synthesis through the esterification of palmitic acid with methanol and also for hydrolysis of ether linkages of dioxane, anisole and cellulose.