【摘要】：介孔結構憑借其高的比表面、孔徑大、孔壁組成以及介觀結構多樣等特點,被廣泛應用于環(huán)境、醫(yī)療和能源等領域。已有的研究對材料的形貌與孔結構控制不夠,合成的方法缺乏改進。常見的介孔碳經(jīng)過磺化后作為固體酸催化劑,用于酯化反應的研究雖有報道,但固體酸催化劑與油脂降酸的構效關系研究鮮有報道。本文利用PF為原料,通過EISA法合成了介孔碳材料,得到了催化劑的比表面積、孔道有序性和孔容大小等數(shù)據(jù),最后深入探討了介孔材料與油脂降酸構效關系,不僅可以豐富介孔碳材料的內容,也對促進氣相酯化降酸反應的進行有著重要的意義。獲得主要研究結論:(1)利用一步法合成了不同碳源催化劑,其中厭氧發(fā)酵殘留物固體酸催化性能最佳。在合成溫度110℃、合成時間120min和硫酸質量濃度為30%的條件下,厭氧發(fā)酵殘留物固體酸催化性能較優(yōu),酯化率可達65.37%。表征得到,多孔碳基固體催化劑為不定形碳結構。同時隨磺化時間的增加石墨化以及磺化程度越來越好,厭氧發(fā)酵殘留物固體酸孔道以微孔為主。當醇油摩爾比為8:1、催化劑用量為4wt%、體系溫度80℃和反應2h后,厭氧發(fā)酵殘留物固體酸酯化降酸的轉化率達到了 76.32%。(2)分別考慮合成方法、模板劑、碳前驅體對合成的一系列樣品有序性和孔類型的影響。表征結果表明:F127或F127:P123=2:1為模版,PF為前驅體,EISA法得到了有序介孔碳基固體酸催化劑,且孔道有序性最好。酯化反應條件:反應溫度110℃、催化劑用量3wt%、反應時間90min。樣品F-E-PF-S酯化降酸效果最佳,轉化率可達到94.20%,樣品F-H-PF-S可達91.50%。F127/P123=2:1時催化劑酯化降酸效果優(yōu)于單獨使用F127,轉化率達到95.10%。因此,最適合成條件:EISA為最適合成方法、酚醛樹脂為前驅體。(3)預聚溫度75℃催化劑有序性最佳,其比表面積為677.97m~2/g,對應的孔徑2.0nm;隨著預聚時間的增加催化劑有序性增強;隨著升溫速率的增加催化劑有序性降低;模版配比為2:1時催化劑有序性最好。(4)選擇比表面積為677.97m~2/g的樣品催化氣相酯化降酸反應,得到的最佳條件為:催化劑用量3wt%、反應溫度110℃、反應時間120min得到酯化降酸轉化率為95.48%;與厭氧發(fā)酵殘留物固體酸比較,介孔催化劑活性明顯更優(yōu),120 min轉化率可達到95.48%,厭氧發(fā)酵殘留物固體酸轉化率僅為76.31%。介孔孔道的增加有利于酯化降酸反應的進行。通過對介孔類催化劑構效關系進行分析,結果表明,催化劑的有序性對降酸反應的速率以及轉化率均存在一定的影響;酯化轉化率隨催化劑的比表面積增加,呈上升趨勢;催化劑孔徑大小對酯化降酸轉化率的影響規(guī)律性不太明顯,后續(xù)有待繼續(xù)研究。
[Abstract]:Mesoporous structures are widely used in environmental, medical and energy fields due to their high specific surface area, large pore size, pore wall composition and various mesoscopic structures. The previous studies have not controlled the morphology and pore structure of the materials, and the synthesis methods are lack of improvement. It has been reported that mesoporous carbon has been used as solid acid catalyst after sulfonation, but the structure-activity relationship between solid acid catalyst and fatty acid deacidification has been rarely reported. In this paper, mesoporous carbon materials were synthesized by EISA method using PF as raw material. The specific surface area, pore order and pore volume of the catalysts were obtained. Finally, the structure-activity relationship between mesoporous materials and fatty acids was discussed. It can not only enrich the content of mesoporous carbon materials, but also promote the esterification and reduction of acid in gas phase. The main conclusions are as follows: (1) the catalysts of different carbon sources were synthesized by one-step method, among which the solid acid catalyst of anaerobic fermentation residue was the best. Under the conditions of synthesis temperature 110 鈩，

本文編號：2448885