【作者】 刘丽娟；

【导师】 王济奎； 王锦堂；

【作者基本信息】 南京工业大学 ， 应用化学， 2006， 硕士

【摘要】 氧氯化锆（ZrOCl₂·8H₂O）溶胶-凝胶法制备纳米二氧化锆粒子的存在着在制备过程中会发生团聚、后处理程序复杂、影响粉体性能等缺点。在应用方面,多数研究集中在二氧化锆在材料工程的应用。本论文研究了一种新颖而又简捷的粉体制备方法,不仅制得了性能优良的二氧化锆超细粒子,而且有效避免了粉体发生硬团聚现象。并对其进行改性,制成纳米二氧化锆固体超强酸催化剂。另外,对纳米二氧化锆固体超强酸在萘齐聚反应的催化作用进行了初步的研究。首先,对纳米二氧化锆的制备工艺进行了研究。用氧氯化锆制备纳米二氧化锆粉末有着显著的优点,成本低,工艺简单,为了得到粒径小且分布均匀的二氧化锆粒子,本实验考察了反应物配比、反应温度、溶液pH值、煅烧温度、时间等条件对产物粒径的影响,获得了最佳工艺条件。并通过XRD、TEM ZETASIZER等手段对它们的结构、粒径、粒度分布、形貌等进行了表征。结果表明,在氧氯化锆溶液初始浓度为1.0 mol/L、醇水的体积比为5:1、添加量为每100ml溶液1ml乙二醇单甲醚的有机分散剂、使用饱和碳酸氢铵溶液作为沉淀剂、并采用正滴的方法、使溶液保持在pH为9附近、陈化时间为24h、采用真空冷冻干燥方式、煅烧温度为500℃的条件下,可以得到粒径80nm左右,形貌较好,产率为96.8%的纳米二氧化锆。其次,利用制得的纳米二氧化锆,制备固体超强酸。使用ZETASIZER、TG-DSC等手段表征了纳米二氧化锆固体超强酸的粒度,成分及比表面积。另外,通过Hammett指示剂法测定酸强度,艾士卡法测定硫含量发现,固体酸催化剂的制备条件对催化剂性质的影响很大。实验的结果得到当浸渍硫酸浓度为1.5mol/L,催化剂煅烧温度为550℃时,煅烧时间3h时,得到的纳米二氧化锆固体超强酸的酸性最强,H0≤-14.50,硫含量8.6%。最后,将制得的固体酸催化剂应用于萘的齐聚反应。传统上萘的齐聚反应使用的催化剂为金属的氯化物或氟化物,但可能造成氯的残留,影响产物的应用,氟离子又可能造成环境污染问题。纳米二氧化锆应用于此反应可以解决上述问题。本文考察了在反应过程中的催化剂与原料的比例、反应温度、反应时间对萘转化更多还原

【Abstract】 Nano-sized ZrO₂ powder has been prepared by ZrOCl₂·8H₂O in sol-gel process in which the powders would agglomerate and would impact their functions. On the other, the process after reaction is complex. The uses of nano-ZrO₂ almost focus on the application of material project. In this article, we studied a novel and simple method by which we can not only have fine ZrO₂ powders but also avoid the possibility of agglomerate. Then we made super acid catalyst with the nano-ZrO₂ and studied oligomerization on naphthalene with the catalyst.At first, we studied the preparation of nanometer ZrO₂.The process of preparing with ZrOCl₂·8H₂O has some obvious advantages such as cheap and simple reaction. But the phenomenon of agglomerate is serious and the size distribution of ZrO₂ powders is always wide. In order to have fine and narrow distributed ZrO₂, we studied the method in this article. Some conditions such as the proportion of reactant, reaction temperature and reaction time. The size, size distribution, appearance and composition of the particles were observed by XRD, TEM and ZETASIZER. The optimal conditions are as follows: the concentration of ZrOCl₂·8H₂O solution is 1.0 mol/L, the volume ratio of ethanol and water is 5:1, the amount of ethyleneglycol monomethyllether is 1%, precipitator is saturated NH4HCO3 solution, the value of pH is at about 9, aging time is 24 hours, calcinations temperature is 500℃. At the above conditions, the product has an average diameter of 80nm with good dispersion and sphere-shaped and the yield of the product is 96.8%.Secondly, solid super acid was made by nanometer ZrO₂. ZETASIZER、TG-DSC are used to characterized the sample. An influence of SO₄^2-/ZrO₂ preparatory process on its catalytic properties was preliminarily investigated by using Hammett indicator. It was found that the sample has the most acid strength and catalytic activation at the condition of the follows: H2SO4 concentration is 1.5 mol/L, calcinations temperature is 550℃, and calcinations time is 3 hours. The nano-grade SO₄^2-/ZrO₂ solid super acid prepared had the strongest acid strength, H0≤14.50. At last, the solid super acid SO₄^2-/ZrO₂ was used as catalyst in the oligomerization of naphthalene. In this reaction the catalyst is chloride or fluoride of metal traditionally更多还原