Synthesis Of Magnetic Nanometer Solid Superacid SO₄～(2-)/ZrO₂-Ni_0.5Fe_2.5O₄ And Its Catalytic Property Research

Solid superacid catalyst is a new type of catalytic matrerials which have been developed in recent years. This catalyst has been proved to be a very effective from the viewpoint of activity,selectivity and reusability in the preparation of various important chemicals which have a number of difficulties with homogeneous catalysts,and can overcome such as corrosion, pollution, more vice-reactions, difficult of separation, and low selectivity. Solid superacid SO42-/ZrO2 is a kind of them, which has such advantages as high activity, hydrothermal stability, easy of separation of production with catalyst,non-corrosion and non-enviroment polluting. In recent years, with the development of nano technology, nano-sized SO42-/ZrO2 is being widely concerned by many scholars for its high specific surface and catalyst and catalystic activity .In this paper,the study and development of the catalyst has been described, and according to the idea of magnetizing catalyst ,we have brought forward the preparation method of magnetic solid superacid, and used it in esterification for detecting its performace. We also carried out some pilot study of adding lanthanum in this catalyst.At fist, we prepared the magnetic fluids with micro-particulate by means of chemical coprecipitation and prepared magnetic solid superacid SO42-/ZrO2-Nio.5Fe2.5O4 via precipitation in aqueous solution. Its parameters such as particulate diameter, crystal configuration and temperature of crystallization have been analyzed by means of XRD, TEM and DTA, and the results showed that the particle size of this catalyst is around 50nm, the transformation from ZrO2(t) to ZrO2(m) has been delayed for mixing of lanthanum into this catalyst, i.e. crystallization temperature has been enhanced. At the same time, we studied the influences of the preparation condition, baking temperature,baking time, adding amount of magnetic materials, consistency of impregnating solution on it. In the end, the catalyst was used in the reaction of the esterification between acetic acid and n-batunol,which proves that the catalyzing activity of this magnetic solid superacid catalyst SO42-/ZrO2/Ni0.5Fe2.5O4 can reach 91.3%,its selectivity approaches to 100%,and it takes on fine rate of reclaiming.