γ-Al_2O_3载体孔内原位合成水滑石

The in-situ Synthesis of LDH in the Pores of γ-Al_2O_3

以尿素为沉淀剂,利用γ Al2O3的内孔表面铝源原位合成水滑石.考察了晶化时间、晶化温度、初始溶液浓度、原料配比对原位合成水滑石的影响.实验中发现晶化6h,MgAlCO3 LDH的晶体结构已趋于完整,晶化时间大于6h时会有NH4Al(OH)2CO3·H2O杂相生成.在实验条件范围内,生成的一次粒子大小随着晶化时间的延长逐渐增大,随着晶化温度的升高、初始溶液浓度的增大而减小.

The in situ surface synthesis of hydrotalcite in the pores of γAl2O3 was performed with urea as preciptator. A series of factors about surface synthesis of hydrotalcite, such as aging time, aging temperature, the mol ratio of the raw materials and the concentration of the raw materials was investigated. The samples were characterized by XRD, DTATG and IR. Experimental results show that as aging time reaches 6 h, the crystal structure of MgAlCO3LDH is near perfect. When the aging time is over 6 h, an inpurity phase of NH4Al(OH)2CO3·H2O will appear. Under the conditions of experiment, the particle size of LDHs increases with increasing aging time, and decreases with increasing the initial concentration of solution becomes biggel and the aging temperature.