L型沸石合成过程中的晶型控制

Crystal control of L zeolites during its synthesis

综述了原料、凝胶组成、晶化条件及添加剂等合成变量对L型沸石晶型调控的影响。选择不同的硅源和铝源,得到的晶粒尺寸和形貌有所差别;凝胶中水含量越高,碱度越低,晶化温度越高,晶粒的长径比越大,呈长圆柱体;添加导向剂和金属导致晶粒尺寸变小,添加醇类化合物可使晶粒长径比减小,添加模板剂促进晶粒变大,提高晶型的完好性。

The effects of the synthesis variables such as raw materials, gel composition, crystallization conditions and additives on the crystal size and morphology of zeolite L were summarized. The changes of the silicon and aluminium sources resulted in the differences of the crystal size and morphology. The higher the water content of the gel, the lower the alkalinity, the higher the crystallization temperature, and then the greater the length to diameter ratio of the crystal particles, the morphology of which demonstrated a shape of long cylinder. The addition of the directing agents and certain metals led to the decrease of the crystal size, and the alcohols could reduce the ratio of length to diameter of the particles, while the templates increased the crystal size and enhanced the integrality of morphology.