化学学报 ›› 2001, Vol. 59 ›› Issue (9): 1367-1371. 上一篇    下一篇

研究论文

新型固体酸催化剂Nafion/SiO2的制备与表征

王海;王建武;徐柏庆;邱显清   

  1. 清华大学化学系一碳化学与化工国家重点实验室
  • 发布日期:2001-09-15

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

Wang Hai;Wang Jianwu;Xu Baiqing;Qiu Xianqing   

  • Published:2001-09-15

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。

关键词: 催化剂, 氧化硅, 溶胶-凝胶法, 全氟磺酸树脂, 固体酸, 热稳定性

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.

Key words: CATALYST, SILICON OXIDE, SOL-GEL PROCESS, SOLID ACID, THERMAL STABILITY

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