CAJ | 학술논문

采用化学共沉淀法制备了SO_4~(2-)/ZrO_2/Fe_3O_4/TiO_2磁性固体酸,利用X射线衍射、示差扫描量热、Mssbauer谱、透射电子显微镜、NH_3-程序升温脱附、N_2吸附-脱附、磁滞回线等手段对磁性固体酸的结构与性质进行了表征.表征结果显示,磁性基质Fe_3O_4及TiO_2的引入有利于四方晶相ZrO_2(t)的稳定;ZrO_2晶体生长取向于ZrO_2(t)的(101)方向,(101)晶面间距为0.293 nm;Mssbauer谱中双峰的存在表明磁性基质Fe_3O_4的存在;在室温下磁性固体酸具有超顺磁性.以乙酸乙酯的合成为探针反应,考察了SO_4~(2-)/ZrO_2/Fe_3O_4/TiO_2磁性固体酸催化剂的催化性能,实验结果表明,外加磁场使酯化反应的醋酸转化率提高到92%.
채용화학공침정법제비료SO_4~(2-)/ZrO_2/Fe_3O_4/TiO_2자성고체산,이용X사선연사、시차소묘량열、Mssbauer보、투사전자현미경、NH_3-정서승온탈부、N_2흡부-탈부、자체회선등수단대자성고체산적결구여성질진행료표정.표정결과현시,자성기질Fe_3O_4급TiO_2적인입유리우사방정상ZrO_2(t)적은정;ZrO_2정체생장취향우ZrO_2(t)적(101)방향,(101)정면간거위0.293 nm;Mssbauer보중쌍봉적존재표명자성기질Fe_3O_4적존재;재실온하자성고체산구유초순자성.이을산을지적합성위탐침반응,고찰료SO_4~(2-)/ZrO_2/Fe_3O_4/TiO_2자성고체산최화제적최화성능,실험결과표명,외가자장사지화반응적작산전화솔제고도92%.
Nano magnetic solid acids SO_4~(2-)/ZrO_2/Fe_3O_4/TiO_2 were prepared by co precipitation. Obtained samples were characterized by XRD, DSC, Mssbauer, TEM, NH_3 TPD,N_2 adsorption desorption and magnetic hysteresis loop. The introduction of TiO_2 and magnetic substrate Fe_3O_4 were beneficial to keep tetragonal crystalline structure of ZrO_2 from transferring to monoclinic form in calcination, ZrO_2 crystals grew along the direction of (101) crystal plane. The interplanar distance of ZrO_2(t) (101) plane were 0.293 nm. Mssbauer results revealed the existence of magnetic substrate Fe_3O_4 particles. Magnetic measurement showed superparamagnetism of solid acid catalyst at ambient temperature. Taking synthesis of ethyl acetate as probe reaction for evaluating the activity of nano magnetic solid acid SO_4~(2-)/ZrO_2/Fe_3O_4/TiO_2 catalyst, the conversion of acetic acid in the esterification mounted to 92% in external magnetic field and aggregation of nano magnetic solid acid catalyst was avoided.