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用BET低温氮吸附、压汞、扫描电镜等方法考察了硫酸钛-氨水解法制备的二氧化钛载体的孔结构和强度。发现最终湿凝胶的pH值强烈地影响二氧化钛载体的孔结构,各种pH的胶体所制备的载体具有不同的总孔体积(≥50埃)和孔径分布(本文中孔径都是指孔半径)。二氧化钛载体的强度随着载体总孔体积的增加,特别是>300埃的大孔部分孔体积的增加而迅速下降。不同pH的胶体在30℃干燥后,孔结构就存在很大差别,使孔结构变化较大的温度范围是30～150℃。提高载体强度的有效措施是采用较低pH值的胶体,pH值以5.0左右为好。
The pore structure and strength of the titania carrier prepared by the hydrolysis of titanium sulfate - ammonia were investigated by low temperature nitrogen adsorption, mercury intrusion and scanning electron microscopy. The pH of the final wet gel was found to strongly affect the pore structure of the titania support. The carriers prepared for various pH colloids had different total pore volume (> 50 Angstroms) and pore size distribution (both pore diameters herein refer to pore radius) . The strength of the titania support decreases rapidly with an increase in the total pore volume of the support, in particular with an increase in the volume of the macropore pores of> 300 angstroms. When the colloids of different pH are dried at 30 ℃, the pore structure is very different, and the pore structure changes greatly at a temperature range of 30-150 ℃. An effective measure to increase the strength of the carrier is to use colloids of lower pH, preferably at a pH of about 5.0.