磺酸功能化三维有序大孔材料的制备与催化性能研究

采用模板法, 用正硅酸乙酯和3-巯丙基-三甲氧基硅烷的混合溶胶, 在聚苯乙烯胶晶间隙中原位转化, 除去模板后用双氧水将巯基氧化成磺酸基, 首次成功地制备了大孔规整排列的3DOM SiO₂-SO₃H材料. 样品用SEM, EDS, FT-IR等方法进行了测试表征. 结果表明, 所得到材料的三维大孔结构规整性十分好, 大孔孔径大约250 nm, 并由大约80 nm的小孔相连; 磺酸基很好地嵌入孔壁基质中, 吡啶吸附测定显示了典型的质子酸特征, 而且酸中心随硫含量增加而增多. 对乙酸与正丁醇的酯化反应显示了良好的催化性能, 磺酸含量越大, 催化活性越高. 这一研究为开发新型高效的固体酸催化剂提供了很有意义的结果.

Preparation and Catalytic Properties of Sulfonic Functionalized 3DOM Materials

Using templated method, sulfonic functionalized three dimensional ordered macroporous (3DOM) SiO2-SO3H hybrid materials have been first prepared via in situ transformation of mixed sol com- posed of tetraethoxysilane (TEOS) and (3-mercaptopropyl)trimethoxysilane (MPTMS) infiltrated in the in- terstitial voids of polystyrene colloidal crystal, and followed extraction of template and oxidation of thiol groups to sulfonic groups with H2O2. Samples were characterized by SEM, EDS, FT-IR methods. The re- sults showed that synthesized materials possessed well 3DOM structure. The pores were about 250 nm and interconnected by small channels of 80 nm. Sulfonic acid groups had been well anchored into structure-wall. The determination of pyridine adsorption of samples revealed that materials have a typic characterization of proton acid, and the proton acid centers increased with the increase of S content. Catalysts showed good performance in esterification of acetic acid with n-butanol, moreover, the higher content of sulfonic acid is, the more active catalysts are. This study provided significant results for development of new high perform- ance solid acid catalysts.