【作者】 刘涛；

【导师】 张一敏；

【作者基本信息】 武汉理工大学 ， 矿物加工工程， 2010， 博士

【摘要】 钛交联蒙脱石(Ti-PILCs)拥有独特的层间结构,具有比表面积大、热稳定性高,以及催化活性和光敏性好等优异的物化性能,近年来引起了人们极大的关注,它在石油催化、环境保护、精细化工及材料科学等领域显示了广阔的应用前景。本文以鄂东某地产钙基膨润土矿为研究对象,通过分散提纯精制、钛交联剂制备、钛交联蒙脱石多孔材料合成、钛交联蒙脱石材料层间结构研究等过程,成功制备出钛交联蒙脱石多孔材料。首先对鄂东某地产钙基膨润土矿采用湿法提纯工艺,以焦磷酸钠为改型剂,在适宜的工艺条件下,精制出了性能优良的高纯钠基蒙脱石(d001=1.28 nm),并以此为基质进行Ti-PILCs的制备。再分别以TiCl4为钛源(采取水解法),以钛酸正丁酯[Ti(n-C4H9O)4]为钛源(采用溶胶-凝胶法),制备了一系列钛交联蒙脱石复合材料(Ti-PILCs),并对HCl浓度、Ti/土比、H/Ti摩尔比、交联温度等主要合成条件进行了讨论。结果表明,以Ti(n-C4H9O)4为钛源,采用溶胶-凝胶法,在蒙脱石悬浮液浓度=1.0%、Ti/土=20 mmol/g, H/Ti=2.0 mol/mol、[HCl]=5 mol/L、V水/V丙酮=1:2,反应时间为3 h,室温交联,可制得层间距d001值达3.74 nm的大孔结构Ti-PILCs,且比表面积可达409.1 m2/g；交联产物的孔道主要是集中在2-4 nm范围内的中孔,热稳定性较好。然后对交联样品进行焙烧研究,得出焙烧温度、焙烧时间、焙烧升温速度、焙烧气氛等条件对Ti-PILCs材料焙烧样品的物化性能有决定性的影响。经焙烧后Ti-PILCs的d001值分别由焙烧前的3.74 nm下降到d600℃=3.67 nm、d900℃=3.33nm,比表面积由409.1 m2/g下降至S600℃=374.3 m2/g、S900℃=358.2 m2/g,焙烧后的Ti-PILCs层间域有序度提高,孔结构趋于规整,热稳定性大于900℃。研究了钛交联蒙脱石多孔材料的层间结构和性能,并对Ti-PILCs材料应用X射线衍射(XRD)分析、比表面与孔径分布测定、红外分析(FT-IR)、失重差热分析(TG-DSC)、扫描电镜分析(SEM)、透视电镜分析(TEM)和原子力显微镜分析(AFM)等手段进行了表征,同时对Ti-PILCs的层间结构特征和相关机理进行了探讨。最后将Ti-PILCs作为固体酸催化剂应用于合成二芳基乙烷的Friedel-Crafts烷基化探针反应中,二芳基乙烷的产率最高可达86.33%,说明钛交联蒙脱石具有较好的酸催化性能。所得实验样品的部分指标在同领域处于领先水平。更多还原

【Abstract】 Titanium pillared montmorillonite (Ti-PILCs) has particular macroporous structure, excellent physical and chemical performance such as large specific area surface, high thermal stability, good catalytic activity and photosensitivity, and so on. It attracts people’s great attention in recent years, and shows wide application prospect in the fields of petroleum catalysis, environment protection, industry of fine chemicals and material science, etc.In this paper, a Ca-bentonite ore from Eastern Hubei province has been used as research object to prepare Ti-PILCs, which through dispersation purification, Ti pillaring agent, Ti-PILCs synthesis and interlayer structure study.Under appropriate technical conditions, the Ca-bentonite ore from Eastern Hubei province has been beneficiated by wet sedimentation separation process with sodium pyrophosphate as modification agent, producing an ultrapure Na-montmorillonite(value of d001 1.28 nm) with fine performance, then using it for matrix, a Ti-PILC has been synthesized.Ti-PILCs were obtained with pillaring agents were prepared from TiCl4 and HCl. Ti-PILCs were also obtained with pillaring agent prepared from Ti(n-C4H9O)4 and HCl, using purified Na-montmorillonite in Hubei as the starting clay. The results shows that titanium pillared montmorillonite with the largest pore structure (d001=3.74nm) can be gained using Ti(n-C4H9O)4 as titanium resource, when Ti/clay=20 mmol/g, H/Ti=2.0 mol/mol c(HCl)=5 mol/L and at the room temperature. The largest surface area is also up to 409.1m2/g. The material mostly contains mesopores within 2 nm to 4 nm, and possesses good thermal stability.The Ti-PILCs were calcined in the next step. The results showed that calcined temperature, calcined time, calcined speed and calcined ambience affected the physical and chemical properties of the calcined Ti-PILCs. The surface area of Ti-PILCs was reduced from S60℃= 409.1 m2/g to S600℃=374.3m2/g and S900℃= 358.2m2/g, respectively, and the basal spacing was reduced from d001=3.74 nm (60℃) to d600℃=3.67nm and d900℃=3.33 nm, respectively, after being calcined. It is clear that interbedded ordered degree was rised,and pore structure had tended towards regularity, and the thermal stability is over 900℃.In this paper, the basic structures and characteristic of Ti-PILCs have been studied by using XRD, BET method, FT-IR, TG-DSC, SEM, TEM and AFM, and the porous distribution by which Ti-PILCs were formed have been discussed, and make preliminary research on its formation mechanism.Using Ti-PILCs as solid acid catalyst in preparation of diphenylethane, a Friedel-Crafts probe reaction, the productivity of diphenylethane can reach 86.33% supremely, which shows that Ti-PILCs possesses good acid catalytic performance.Some indicators of the experimental products have taken the lead in the same field.更多还原