The Preparation Of Nanometer Zirconium Dioxide And Application In Naphthalene Oligomerization Reaction

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...