合成磷酸铝和硅磷酸铝分子筛方法的研究

STUDIES ON THE METHODS OF SYNTHESIZING ALUMINOPHOSPHATE AND SILICOALUMINOPHOSPHATE MOLECULAR SIEVES

以有机胺作模板剂,用水热法合成磷酸铝分子筛和硅磷酸铝分子筛.所得样品用x—射线粉末衍射分析,化学分析法和红外光谱等进行表征.考察了合成条件对产物结晶相的影响.合成这两类分子筛最适宜的晶化条件如下:晶化温度为150～180℃;反应混合物中Al_2O_3/P_2O_5摩尔配比接近1;初始水凝胶的pH值在4.9和7.0之间;初始反应混合物的搅拌时间在25min以上.此外,给出了在不适宜制备条件下合成这两类分子筛时所得四种致密相AlPO_4的x—射线粉末衍射数据.

The aluminophosphate and silicoaluminophosphate molecular sieves were synthesized hydrothermally using organic amines as templating agents. The saraples obtained were characterized by X—ray powder diffraction analysis, Chemical analysis, and infrared spectra, etc. The influence of some of the synthesis conditions on thc crystalline phases of product has been investigated. The optimal crystallization conditions are as follows: The crystallization temperarure is equal to 150～180℃. The molar ratio of A1_2O_3/P_2O_5 in the reaction mixture should be approximately equal to 1. The initial hydrogel has a pH value between 4.9 and 7.0. The stirring time of the starting reaction mixture must be above 25 minutes. Additionally, x—ray powder diffraction data of four kinds of dense phases AlPO_4 which are obtained in the syntheses of aluminophosphate and silicoaluminophosphate molecular sieves in the case of the use of the unsuitable preparation conditions are given.