新型固体酸催化剂Nafion/SiO2的制备与表征

以正硅酸乙酯为硅源，通过原位溶胶-凝胶技术，制得一类由中孔孔道氧化硅组装的纳米Nafion固体酸催化剂Nafion/SiO2，大大增加了Nafion^(R)NR50酸性中心的暴露量，提高了活性中心的可接近程度。BET,FTIR,TG,SEM和EDX分析表明，NR50的纳米颗粒负载在多孔性SiO2中呈现分布均匀；NH3-TPD分析结果表明，固体酸催化剂Nafion/SiO2具有四种强度不同的酸性位，且其主要酸性中心(SO3H)具有两种不同的热稳定性。

Preparation and characterization of a novel class of solid acid catalyst nafion/SiO2

Due to its superacidic character, high thermal stabioity and chemical resistance, Nafion^(R)NR50 is a very promising catalyst for a wide range of acid-catalyzed reactions. However, its application is ofter limited by its extremely low specific surface area. A new class of solid acid catalysts Nafion/SiO2 with meso-pore structure has been developed using an in situ sol-gel technique, where solutions of Nafion resin were mixed with soluble silicon surces of tetraethylorthosilicate to form a gel. The gel was then dried to give a clear hard glass-like material. These new porous materials showed significantly enhanced activity due to increased accessibility of the Nafion resin-based acid sites. BET, FTIR, TG, SEM and EDX indicated that Nafion resin nanoporrticles were completely trapped and highly dispersed within a porous silica network. NH3-TPD disclosed that the materials have four groups of acidic sites and that the thermal stability of SO3H groups was different.