【作者】 张洋；

【导师】 王新平；

【作者基本信息】 大连理工大学 ， 物理化学， 2010， 硕士

【摘要】 Y型分子筛作为催化剂活性组元或催化剂载体,以其良好的催化活性和高温稳定性,广泛应用于催化裂化和加氢裂化等炼油工业过程中。相对于常规粒度的Y分子筛,纳米Y分子筛具有独特的结构特性,如：更大的外表面积、更多的活性中心、短而规整的孔道,因而具有更高的催化活性、选择性、催化剂寿命及更高的抗硫、氮和重金属污染的性能。本文采用水热法合成纳米NaY分子筛,详细研究了晶化时间、导向剂陈化时间、合成体系的碱度和微波预处理硅铝凝胶等反应条件对合成所得NaY分子筛晶粒尺寸的影响,并用XRD、SEM等手段对合成所得样品进行表征,得到结果如下：(1)上述反应条件均对合成所得NaY晶粒尺寸有直接影响,其中最大的影响因素是合成体系的碱度。为了合成单一晶相的纳米NaY分子筛,晶化温度应选定为90℃,晶化时间为4 h；最佳的硅铝凝胶反应摩尔配比为9.5Na2O：Al2O3：10SiO2：210H2O；导向剂陈化时间为4天,且导向剂中Al2O3的质量占硅铝凝胶总Al2O3质量的10%。(2)研究发现,对硅铝凝胶用微波短时间预处理,有利于小晶粒NaY分子筛的合成,而超声波预处理对合成所得NaY晶粒平均尺寸没有影响。在上述优化条件下,成功合成出了晶粒大小均一、平均晶粒约为90 nm的纳米NaY分子筛。更多还原

【Abstract】 Y-type zeolite as a active catalyst, with its good catalytic activity and high temperature stability, was widely used in catalytic cracking and hydrocracking process. Compared with commercial Y zeolite, Y zeolite with nanosized particals had the unique features, such as greater external surface area, more exposed active sites, short and regular pores, which resulted in a higher catalytic activity, selectivity, longer catalytic lifetime and higher resistance to sulfur, nitrogen and heavy metal pollution performance.In this thesis, the factors affecting preparation of nano-NaY zeolite with hydrothermal synthesis method, such as crystallization time, aging time of nucleation gel, alkalinity of the precursor for the synthesis NaY were investigated in detail. The samples synthesized were characterized by XRD and SEM techniques. The corresponding results are as follows:(1) The results indicated that the most important factor affecting the synthesis of nano-NaY is alkalinity of the synthesis system. For synthesizing pure nano-NaY zeolite, the best molar composition of synthesis system is 9.5Na2O:Al2O3:10SiO2:210H2O, and the aluminosilicate gel obtained should be crystallized at 90℃for 4 hour. The nucleation gel should be aged for four days before being added to hydrothermal kettle in wt.10% of the synthesis precursor accounted in moles of Al2O3.(2) It was found that treating the aluminosilicate gel in microwave for several minutes before hydrothermal crystallization benefits to the nanosized NaY synthesis, while ultrasonic pretreatment do not work. Under the optimized synthesis condition, NaY zeolite with uniform grain size of about 90 nm was successfully obtained.更多还原