Ag/SiO_2-ZnO-CeO_2催化剂上甘油与苯胺液固相高效催化合成3-甲基吲哚  

Liquid-solid phase efficient synthesis of 3-methylindole from glycerol and aniline over Ag/SiO_2-ZnO-CeO_2 catalyst

作　　者：石雷[1] 杜秀芳 任丽婷 郝文文 赵丹[1] SHI Lei;DU Xiufang;REN Liting;HAO Wenwen;ZHAO Dan(School of Chemistry and Chemical Engineering,Liaoning Normal University,Dalian 116029,China)

机构地区：[1]辽宁师范大学化学化工学院,辽宁大连116029

出　　处：《辽宁师范大学学报（自然科学版）》2018年第3期345-352,共8页Journal of Liaoning Normal University:Natural Science Edition

基　　金：国家自然科学基金资助项目(21576128)

摘　　要：3-甲基吲哚作为一种应用极广的氮杂环化合物,可以合成许多在工、农、医等领域有重要用途的化学品.以生物柴油副产物甘油为主要原料与苯胺反应合成3-甲基吲哚是目前最理想的合成方法,不仅价格低廉,而且绿色环保.以Ag/SiO_2为催化剂,向其添加ZnO及CeO_2助剂,在不锈钢高压反应釜中通过液固相反应一锅高效催化合成3-甲基吲哚,通过H2程序升温还原、X射线粉末衍射、透射电镜、NH3程序升温脱附和热重等手段对催化剂进行表征.结果表明:加入ZnO助剂能增强活性组分银与SiO_2载体的相互作用,有效提高银在SiO_2-ZnO表面的分散度,并抑制银粒子在反应过程中的烧结.CeO_2助剂的加入能在一定程度上减弱催化剂的中强酸酸性,从而抑制反应过程中积碳的形成.当ZnO和CeO_2助剂含量分别为1.00和0.04mmol/g时,Ag/SiO_2-ZnO-CeO_2催化剂表现出很高的催化性能,反应16h,3-甲基吲哚的收率可以达到70%.该催化剂重复使用5次,其目标产物收率尚能达到63%.3-Methylindole,a nitrogen heterocyclic compound with very wide application,can synthesize many chemicals that have important uses in the fields of industry,agriculture and medicine.The synthesis of 3-methylindole from the reaction of glycerol,which is the by-product of biodiesel and used as a main raw material,with aniline is the most ideal method at present.It is not only inexpensive,but also environmentally friendly.In this paper,3-methylindole was efficiently synthesized in a stainless steel autoclave through one-pot liquid-solid reaction over Ag/SiO2 catalyst doped with ZnO and CeO2 promoters.The catalysts were characterized by temperature-programmed reduction of H2（H2-TPR）,X-ray diffraction（XRD）,transmission electron microscopy（TEM）,temperature-programmed desorption of NH3,thermogravimetric（TG）analysis,etc.The results indicated that ZnO could enhance the interaction between Ag and the support,as a result,the dispersion of Ag particles on the surface of SiO2-ZnO support greatly improved,and the sintering of Ag particles during the reaction effectively inhibited.The addition of CeO2 promoter can weaken the acidity of the middlestrong acid of the catalyst to a certain extent,thereby the carbon deposition during the reaction was suppressed greatly.When the contents of ZnO and CeO2 promoters were 1.00 and 0.04 mmol/g,respectively,the Ag/SiO2-ZnO-CeO2 exhibited very good catalytic performance.The yield of 3-methylindole reached 70%at the reaction time of 16 hand 63%yield of the aimed product could be remained after the catalyst was reused five times.

关 键 词：3-甲基吲哚 Ag/SiO2-ZnO-CeO2催化剂 甘油 苯胺 液固相催化反应 

分 类 号：O643.322[理学—物理化学]