不同水解条件下Ti-MCM-41介孔分子筛的合成及其催化氧化脱硫性能

摘要

Ti-MCM-41 mesoporous materials were synthesized through improved hydrothermal method with solution of cetyltrimethylammonium bromide (CTAB) and sodium hydroxide as template, tetraethylorthosilicate (TEOS) as silica source,tetraethylorthosilicate (TBOT) as titanium source. The influence of temperature of hydrolysis (30℃、60℃) and inhibitors of alcohols were investigated respectively. Products were characterized by XRD,SEM,TEM and other means. The results indicate that the molecular sieves obtained exhibit regular long-range ordered hexagonal mesoporous structure. The sample at hydrolysis temperature of 30℃ shows better crystallinity and long-range ordered structure. Desulfurization rate reached 96.7%under the condition:catalyst amount 0.1g/10mL(oil), reaction time 30min and desulfurization temperature 40℃. It can be summarized that lattice defects and poor long-range order are in favor of the removal of sulfur from diesel.%采用改进后的水热合成法，以十六烷基三甲基溴化铵（CTAB）与氢氧化钠的混合溶液为模板剂，正硅酸乙酯（TEOS）为硅源，钛酸四丁酯（TBOT）为钛源，合成Ti-MCM-41分子筛。分别考察了水解合成温度（30℃、60℃）、添加醇类络合剂抑制TBOT水解对其合成的影响。使用XRD、SEM、TEM等手段对分子筛催化剂样品进行了表征，发现合成的分子筛均有规则的长程有序六方介孔结构，30℃下合成的样品的结晶度和长程有序性更好，在催化剂用量为0.1g/10mL(油)、脱硫时间30min、脱硫温度40℃的实验条件下，60℃下水解合成的分子筛脱硫率达到96.7%。实验结果表明，晶格缺陷多、长程有序性差有利于脱除柴油中的硫。