CAJ | 학술논문

采用后接枝法对介孔分子筛载体SBA-15接枝伯胺基(PA)、仲胺基(SA)、叔胺基(TA)和哌嗪基(PP)4种有机胺官能团制得4种催化剂,用XRD、BET、TG、SEM和元素分析仪对所制备的固体碱催化剂进行表征,以糠醛、丙酮为生物油模型化合物研究了4种催化剂的醇醛缩合反应性能,考察了接枝环境、接枝剂官能团、溶剂及温度对糠醛转化率及糠叉丙酮( FA)与二糠叉丙酮( F2 A)选择性的影响。结果表明,XRD及SEM图谱显示后接枝法胺基化改性SBA-15保留了载体高度有序的孔道结构,BET分析结果表明接枝后SBA-15比表面积从829 m2/g下降至292 m2/g(哌嗪基SBA-15),经TG与元素分析计算得到N的接枝量为0.6~1.0 mmol/g；采用N2保护条件进行接枝反应可提高催化剂的催化性能,使用质子型溶剂、升高反应温度均有利于提高糠醛转化率和目标产物选择性,4种碱性官能团中伯胺基具有最高的催化活性和产物选择性。 N2保护环境下以H2 O为溶剂,糠醛和丙酮在 PA/SBA-15催化下80℃经8 h反应后,糠醛转化率为82.6%,FA和F2 A选择性分别为41.4%、8.7%。
채용후접지법대개공분자사재체SBA-15접지백알기(PA)、중알기(SA)、숙알기(TA)화고진기(PP)4충유궤알관능단제득4충최화제,용XRD、BET、TG、SEM화원소분석의대소제비적고체감최화제진행표정,이강철、병동위생물유모형화합물연구료4충최화제적순철축합반응성능,고찰료접지배경、접지제관능단、용제급온도대강철전화솔급강차병동( FA)여이강차병동( F2 A)선택성적영향。결과표명,XRD급SEM도보현시후접지법알기화개성SBA-15보류료재체고도유서적공도결구,BET분석결과표명접지후SBA-15비표면적종829 m2/g하강지292 m2/g(고진기SBA-15),경TG여원소분석계산득도N적접지량위0.6~1.0 mmol/g；채용N2보호조건진행접지반응가제고최화제적최화성능,사용질자형용제、승고반응온도균유리우제고강철전화솔화목표산물선택성,4충감성관능단중백알기구유최고적최화활성화산물선택성。 N2보호배경하이H2 O위용제,강철화병동재 PA/SBA-15최화하80℃경8 h반응후,강철전화솔위82.6%,FA화F2 A선택성분별위41.4%、8.7%。
Solid basic catalysts were synthesized by post-grafting four different organic amines, i. e. primary amine ( PA ) , secondary amine(SA), tertiary amine(TA) and piperazidine(PP) to mesoporous SBA-15. The samples were characterized by X-ray diffraction, nitrogen adsorption, thermogravimetric analysis, scanning electron microscopy and elemental analysis. The activity of prepared catalysts was tested in aldol condensation reaction of bio-oil model compounds (furfural and acetone). The influence of graft reaction conditions, different functional groups of amine, solvents and temperature on conversion of furfural and selectivity of FA and F2 A were investigated. The results indicated that the prepared samples retain excellent ordered mesoporous structure with the amino loading at 0. 6 - 1. 0 mmol/g. The catalytic activity increased when strict N2-pretected grafting condition, protic solvent and higher temperature were used. The catalyst containing primary amine ( N2-pretected grafting condition) shows the best catalytic activity. The highest conversion of furfural (82. 6%) and product selectivity of FA (41.4%) and F2 A(8. 7%) can be achieved after reaction at 80 ℃ for 8 h in H2O solvent.