Developing Brønsted–Lewis acids bifunctionalized ionic liquids based heteropolyacid hybrid as high-efficient solid acids in esterification and biomass conversion

• Published in: Journal of industrial and engineering chemistry (Seoul, Korea) Vol. 92; pp. 200 - 209
• Main Authors: Liu, Yong, Wu, Yuefeng, Su, Miaojun, Liu, Weihua, Li, Xiying, Liu, Fujian
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 25-12-2020; 한국공업화학회
• Subjects: Esterification; Glucose dehydration; Ionic liquids based heteropolyacid hybrid; Reaction kinetics; Solid acids; 화학공학; Glucose dehydration; Solid acids; Ionic liquids based heteropolyacid hybrid; Esterification; Reaction kinetics
• ISSN: 1226-086X; 1876-794X
• DOI: 10.1016/j.jiec.2020.09.005

Ionic liquids based heteropolyacid hybrid (ILs-HPA) with both Brønsted and Lewis acid sites were prepared, which exhibit superior activities in esterification and biomass conversion.
[Display omitted]
A class of Brønsted–Lewis acid bifunctionalized ionic liquids based heteropolyacid hybrid (BLA-ILs-HPA) solid acids were developed by combining the double sulfonic groups grafted, ionic liquids based heteropolyacid hybrid with Lewis acidic centers (M = Zn, Co, Fe, Ni, Cu). The prepared BLA-ILs-HPA show both Brønsted and Lewis acidic sites with extremely-high acid strength and enhanced stabilities, as determined by FT-IR, Py-IR, TG, XPS and 31P solid state NMR results. BLA-ILs-HPA were successfully applied in esterification camphene with acetic acid to produce isobornyl acetate, and dehydration of glucose to produce 5-hydrozymethylfural. BLA-ILs-HPA show enhanced catalytic activities in comparison with various acid catalysts. The effects of reaction temperatures, initial reactant molar ratio, catalyst dosage, and reaction time were studied in detail. The optimal reaction conditions were obtained, and the experimental data was successfully correlated by a pseudohomogeneous (PH) reaction kinetic model in the temperature range of 313.15–333.15 K. The calculated values obtained by the reaction kinetic model were in good agreement with the experimental data. Moreover, as a heterogeneous reaction catalyst, BLA-ILs-HPA can be recovered by simple treatment. After six times cycling, the decreasing in the catalytic activity of BLA-ILs-HPA could not be observed significantly, suggesting their good reusability.