纳米α-Fe_2O_3的制备及其催化高氯酸铵热分解

PREPARATION OF NANOMETER SIZE α-Fe_2O_3 AND ITS CATALYSIS ON THE THERMAL DECOMPOSITION OF AMMONIUM PERCHLORATE

采用高温水解相转化法制备了纳米级的α Fe2 O3催化剂 ,比较了NaOH、(NH4 ) 2 CO3以及尿素三种沉淀剂的作用效果。对制得样品的尺寸、形貌和晶型等使用纳米粒度仪、透射电镜 (TEM )以及X射线衍射仪 (XRD)进行分析测试 ,结果表明各个样品均为粒度分布均匀、分散性很好的α Fe2 O3纳米粒子。将纳米催化剂按 1 0wt%加入高氯酸铵 (AP)中 ,对混合物进行差热分析仪 (DTA)分析 ,发现添加有纳米α Fe2 O3催化剂样品的AP的分解峰有明显的提前。其中 ,以添加用尿素为沉淀剂的样品 (粒度最小 )的AP分解峰提前最多 ,高、低温分解峰提前分别达到了 78℃和 9 6 6℃ .对以尿素为沉淀剂时催化剂粒径较小的情况进行了分析 。

Nanometer α-Fe2O3 catalysts are prepared by hydrolization in high temperature. The precipitator of NaOH, (NH4)CO3 and urea is used to compare their effects in the process of hydrolization. Nanometer sizer, TEM and XRD are employed to test the profiles and diameters of the product particles. Test results indicate that the products are nanometer size α-Fe2O3 with narrow diameter distribution and good dispersion. The catalyst is mixed with ammonium perchlorate (AP) in 1.0% wt. DTA is employed to analyse the thermal decomposition of the mixture and the pure AP sample. The result implies that the thermal decomposition peak of the sample added with the nanometer α-Fe2O3 catalyst is markedly ahead of the pure AP sample. Among these mixtures added with the nanometer material, the smaller the particle size of catalyst, the more ahead tended to be the thermal decomposition curve peak of AP. And the high and low temperature decomposition curve peaks of AP mixed with the catalyst precipitated by urea are 78°C and 9.66°C ahead respectively. The mechanism of catalysis precipitated by urea and the distinct catalytic action of the particles on the thermal decomposition of AP are analyzed.