纳米固体超强酸催化正戊烷低温裂解反应研究

NANO SOLID SUPERACID CATALYSTS FOR n-PENTANE CRACKING REACTION

采用沸腾回流强迫水解法合成了纳米TiO2粉体，经TEM表征，颗粒近似球形，粒径10～20nm，XRD测试为锐钛矿型。将TiO2粉体用1．0mol／L的H2SO4处理，500℃焙烧，制备了纳米SO4^2-／TiO2固体酸，经Hammett指示剂法及35℃时正戊烷异构化反应验证具有超强酸性（H0〈-14．52，k1〉0）；50℃时催化正戊烷裂解生成异丁烷，产率可达71．78％，并对其裂解机制进行了探讨，初步确认其裂解过程为：正戊烷←→异戊烷←→异丁烷。

The morphology and crystal linity of TiO2, which was prepared by a refluxing method, has been studied by means of TEM and XRD. It was found range of 10-20 nm and existed in the form of anatase. that the particles of TiO2 was sphere, in the SO4^2-/TiO2 was prepared by immersing TiO2 into dilute H2SO4 （1 mol/L） followed by calcinting at 500℃. Characterized by Hammett indicator and n-pentane isomerization reaction at 35℃, SO4^2-/TiO2 was proved a superacid （H0≤ 14. 52, k1〉 1. 232×10^-2）. The results showed that the use of SO4^2-/TiO2 resulted in 71.78% yield of i-butane in n-pentane cracking reaction at 50℃. The mechanism of the cracking reaction was also investigated. It was believed that the process of n pentane cracking reaction proceeded as follows： n-pentane←→ i-pentanee←→i-butane.