华东理工大学学报（自然科学版）2018，Vol.44Issue(2)：150-154,167,6.DOI:10.14135/j.cnki.1006-3080.20170418002
活性炭基疏水性固体酸催化剂的制备及其在乙醇酯化中的性能
Preparation of Activated Carbon-Based Hydrophobic Solid Acid Catalyst and Its Performance in Esterification of Ethanol
摘要
Abstract
Water produced in the synthesis of ethyl acetate from acetic acid and ethanol can combine with the solid acid catalyst,which results in the loss of active components and reduction of the catalytic activity.Zirconium sulfate(ZS)is a kind of solid acid catalyst with excellent esterification catalytic activity and selectivity.In order to improve the stability of ZS,ZS-AC was prepared by loading ZS over the surface of coconut shell-based activated carbon(AC),and then ZS-AC was modified with silane groups to prepare the hydrophobic solid acid catalyst ZS-AC-Cn,where n was the alkyl chain carbon atom numbers.The Fourier transform infrared(FT-IR)spectra revealed that the solid acid catalysts were successfully grafted with silane group,and the alkyl chain length had a great influence on the hydrophobicity of the catalyst. The liquid-solid contact angles increased in the following order:ZS-AC(40.5°)<ZS-AC-C4(94.7°)<ZS-AC-C7(121.2°)< ZS-AC-C8(136°).The reactivity and reusability of these four types of catalysts were investigated at a reaction temperature of 105 ℃.The results showed that the catalytic activity increased with the increasing of the alkyl chain length,and the catalyst treated with C7H16O2Si had the highest activity and stability.Thermogravimetric analysis(TG)showed that the hydrophobic catalyst had a better thermal stability compared to the hydrophilic catalyst.When the molar ratio of acetic acid to alcohol was 4:1,the mass ratio of catalyst to alcohol was 12%,and the reaction time was 4.5 h,the maximum conversion of ethanol reached 98.8% and the yield of ethyl acetate reached 97.2%.At this point,the esterification reaction approached the chemical equilibrium.Moreover,the hydrophobic catalyst was stable in the presence of water which showed the conversion of ethanol was about 92% after repeated use for 4 times.关键词
硫酸锆/活性炭/硅烷/疏水改性/酯化反应Key words
zirconium sulfate/activated carbon/silane/hydrophobic modification/esterification分类
化学化工引用本文复制引用
李洁文,凌丹,张维义,张希宝,程振民..活性炭基疏水性固体酸催化剂的制备及其在乙醇酯化中的性能[J].华东理工大学学报（自然科学版）,2018,44(2):150-154,167,6.基金项目
国家自然科学基金(21676085) （21676085）
