掺杂La_2O_3的硫酸钛在缩醛(酮)反应中的催化活性

Catalytic Activity of Titanium Sulphate Doped La_2O_3 in Acetal(Ketal) Reaction

硫酸钛掺杂La2O3后经高温焙烧制得一种新型固体酸催化剂。用环己酮缩乙二醇反应表征其催化活性的反应条件为环己酮200mmol,n(环己酮)∶n(乙二醇)=1.0∶1.5,带水剂环己烷15mL,硫酸钛催化剂[w(La2O3)0.05,400℃焙烧3h]用量4.1%(以环己酮质量计),回流分水1h,收率94.5%。结果表明,催化活性随La2O3含量的增加而升高,随焙烧温度的升高而降低。催化剂吸附吡啶的红外光谱证实催化剂表面存在明显的Brnsted酸中心和Lewis酸中心。该催化剂对其它缩醛(酮)反应也有催化活性。

A new type of solid acid catalyst was prepared by calcination of titanium sulphate doped La_2O_3. The catalytic activity was determined by acetal(ketal) reaction between cyclohexanone and glycol. The reaction conditions with yield of 94.5% were as follows: cyclohexanone was 200 mmol, n(cyclohexanone) ∶n(glycol) was 1 ∶1.5, cyclohexane as a water-carrying agent was 15 mL, catalyst[w(La_2O_3) 0.05, calcination temperature 400 ℃ for 3 h] amount was 4.1% based on the mass of cyclohexanone, refluxing time was 1 h. The result showed that the catalytic activity increased with rising of La_2O_3 content and decreased with increasing of calcination temperature. The Brnsted acid centers and Lewis acid centers on the catalyst surface were confirmed by IR spectra of pyridine adsorbed on the catalyst. The titanium sulphate doped La_2O_3 can be used as a catalyst in other acetal(ketal) reactions.