Fe-HMS的合成、表征及催化苯酚羟基化

Synthesis, Characterization and Catalytic Phenol Hydroxylation Performance of Iron-modified Hexagonal Mesoporous Silica

摘要:

以正硅酸乙酯(TEOS)、三氯化铁为原料，十二胺(DDA)为模板剂，采用溶胶–凝胶法合成了铁改性六方介孔硅分子筛(Fe-HMS)，利用XRD、FT-IR、UV-Vis、ESR、TG−DTA、ESEM、TEM及N2吸附-脱附技术对材料结构进行了表征，同时以苯酚羟基化反应为探针考察了Fe-HMS的催化性能。结果表明，Fe-HMS材料由细小的球状纳米粒子组成，材料具有稳定的六方介孔结构，铁已进入六方介孔硅(HMS)载体的骨架；在苯酚羟基化反应中材料显示出较高的催化活性，苯酚的转化率最高可达到46.9%，催化剂经450℃焙烧2 h即可再生，重复使用七次苯酚转化率仍可达到36.4%。

Abstract:

An iron-modified hexagonal mesoporous silica(Fe-HMS) was prepared by sol–gel method with tetraethyl orthosilicate(TEOS), iron trichloride and template reagent of dodecyl amine(DDA) as the raw materials, and the physicochemical properties of the synthesized Fe-HMS were characterized by XRD, FT-IR, UV-Vis, ESR, TG–DTA, ESEM, TEM and nitrogen adsorption–desorption testing technology. Additionally, the catalytic performance of the Fe-HMS on the reaction of phenol hydroxylation was also investigated. The results showed that the Fe-HMS prepared was spherical small particles with stable hexagonal mesoporous structure, and the irons were embedded into the frameworks of the HMS. Furthermore, the Fe-HMS exhibited a higher catalytic activity in the hydroxylation reactions of phenol, and the highest conversion ratio of phenol reached 46.9%. The catalyst could be regenerated after calcined at 450℃ for two hours. The conversion of phenol still could reach 36.4% even after seventh cycle.