加料和煅烧对La3+/SO42-/SiO2-Al2O3固体超强酸粒径影响研究  

Effect of Feeding and Calcining Sequences on Preparation of La3+-modified SO42-/SiO2-Al2O3 Solid Superacid

作　　者：陈桂 谭晓婷[1] 康霞 肖和导 何婷 梁春华 CHEN Gui;TAN Xiao-ting;KANG Xia;XIAO He-dao;HE Ting;LIANG Chun-hua(School of Chemistry and Materials Engineering,Huaihua University,Huaihua 418OOO,China;School of Health,Kaili University,Kaili 556011,China;Key Laboratory of Rare Earth Optoelectronic Materials and Devices y Huaihua University,Huaihua 418000,China)

机构地区：[1]怀化学院化学与材料工程学院,湖南怀化418000 [2]凯里学院大健康学院,贵州凯里556011 [3]稀土光电功能材料与器件怀化学院重点实验室,湖南怀化418000

出　　处：《稀土》2019年第6期126-132,共7页Chinese Rare Earths

基　　金：湖南省科技厅重点项目(2016NK2134);怀化学院科学研究项目(HHXY 2017-07);怀化学院大学生研究性学习和创新性实验计划(201847)

摘　　要：以硫酸铝和硅酸钠为原料,采用共沉淀制备了SiO2-Al2O3。研究了浓硫酸浸渍、掺杂La3+顺序和煅烧顺序对La3+/SO42-/SiO2-Al2O3粒径的影响;通过红外光谱仪、X射线衍射仪、扫描电显镜和激光粒度仪等对其进行了分析表征。得到最佳制备工艺条件:550℃煅烧4 h的SiO2-Al2O3前驱体,掺杂质量浓度2%的La3+溶液改性,550℃煅烧4 h,再用质量浓度75%的浓硫酸浸渍15 h。该条件下La3+/SO42-/SiO2-Al2O3固体超强酸最佳,其粒径为25.261μm,比表面积为3521.783 cm2/cm3。该法制备的固体超强酸粒径较小,比表面积大,结构均一稳定,是一类新型绿色环保的固体酸催化剂。With aluminum sulfate and sodium silicate as raw materials,SiO2-Al2O3catalyst was prepared by coprecipitation method.The effect of impregnated concentrated sulfuric acid and rare earth La ion and calcination modification order on the particle size of SO42-/SiO2-Al2O3was studied.After determining the experimental procedure and order of feeding,the effects of calcination sequence and impregnation sequence on the particle size of SO42-/SiO2-Al2O3were investigated.It was characterized by infrared spectrometer,X-ray diffractometer,scanning electron microscope and laser particle size analyzer.The best preparation conditions were obtained as follows:SiO2-Al2O3precursor was calcined at 550℃for 4 h,modified with La3+,and then calcined for 4 h,and finally impregnated with concentrated sulfuric acid.Under this condition,the particle size of La3+-modified SO42-/SiO2-Al2O3was 25.261μm and its specific surface area was 3521.783 cm2/cm3.The solid acid catalyst has small grain size,large specific surface area and uniforon structure.

关 键 词：固体超强酸 La3+/SO42-/SiO2-Al2O3 共沉淀法 煅烧 

分 类 号：O643[理学—物理化学]