Effective transformation of cellulose to 5-hydroxymethylfurfural catalyzed by fluorine anion-containing ionic liquid modified biochar sulfonic acids in water

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• 作者：Chao Zhang ; Zengtian Cheng ; Zaihui Fu ; Yachun Liu ; Xianfeng Yi ; Anmin Zheng…
• 关键词：Biochar sulfonic acids ; Ionic liquids ; Cellulose hydrolysis ; Reducing sugars ; HMF
• 刊名：Cellulose
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：24
• 期：1
• 页码：95-106
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Bioorganic Chemistry; Physical Chemistry; Organic Chemistry; Polymer Sciences;
• 出版者：Springer Netherlands
• ISSN：1572-882X
• 卷排序：24

文摘

This article first discloses that the fluorine anion-containing ionic liquids-functionalized biochar sulfonic acids (BCSA-IL-F_1–3s), which were simply synthesized by an ionic exchange of 1-trimethoxysilylpropyl-3-methylimidazolium chloride (IL-Cl) grafted on the BCSA with CF₃SO₃H (HF₁), HBF₄ (HF₂), HPF₆ (HF₃), respectively, can efficiently catalyze cellulose hydrolysis into reducing sugars (RSs) and 5-hydroxymethyl furfural (HMF) in water under microwave irradiation. This process provides a very high catalysis efficiency (turnover numbers, 4.03–4.89) at mild temperature (80 °C) for 3 h, but also possesses an excellent repeatability. More outstandingly, they can achieve much higher HMF yields (12.70–27.94%) compared to the IL-Cl-functionalized BCSA catalyst (HMF yields are lower than 0.1%) under the same reaction conditions. This is likely because the introduction of IL-F_1–3s groups can significantly improve the accessibility, acidity and thermal stability of BCSA’s SO₃H sites, as supported by evidence from a solid 31P NMR spectrum and thermogravimetric analysis. It is proposed that the good selectivity for HMF perhaps originates from a co-catalysis action of the IL-F_1–3s and SO₃H groups on BCSA-IL-F_1–3s in the further conversion of RSs to HMF.