Citronellal cyclisation over heteropoly acid supported on modified montmorillonite catalyst: effects of acidity and pore structure on catalytic activity |
| |
Authors: | Abdul Karim Shah Sungsoo Park Hassnain Abbas Khan Umair Hassan Bhatti Praveen Kumar Abdul Waheed Bhutto Yeung Ho Park |
| |
Affiliation: | 1.Department of Fusion Chemical Engineering,Hanyang University,Sangnok-su, Ansan,South Korea;2.Department of Chemical Engineering,Dawood University of Engineering and Technology,Karachi,Pakistan;3.Clean Energy and Chemical Engineering,University of Science and Technology,Daejeon,South Korea;4.Green Energy Process Laboratory, Korea Institute of Energy Research,University of Science and Technology,Daejeon,South Korea |
| |
Abstract: | Citronellal cyclisation to isopulegol is an important intermediate step in the production of menthol. Several heteropoly acids (PTA) supported on modified montmorillonite (MM) catalysts were synthesized and then tested in cyclisation reactions. The prepared samples were characterized by XRD, ICP-OES, FTIR, N2 sorption, NH3-TPD, pyridine adsorption, amine titration and FE-SEM techniques. Effects of post-treatment were studied on montmorillonite pore structure, acidity and catalytic activity. The catalytic activity and isopulegol selectivity improved with acid-treatment and PTA loading. The amount of Lewis acidity of montmorillonite was enhanced with acid-treatment and PTA impregnation. In cyclisation, highest catalytic activity (31.87 mmol cat g?1 min?1) was achieved with 96% isopulegol yield in the use of 20% PTA-MM catalyst. The highest catalytic activity and selectivity were obtained in the presence of higher acidity and strong Lewis acidic sites, whereas effects of pore structure blockage seemed minor. The catalytic activity further decreased with the loss of active acidic sites (L and B) due to PTA decomposition with calcination at a higher temperature. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|