Preparation of Hydrophobic Acidic Metal–Organic Frameworks and Their Application for 5-Hydroxymethylfurfural Synthesis

Abstract

The production of 5-hydroxymethylfurfural (HMF) by the acid-catalyzed dehydration of fructose is of great significance for the comprehensive utilization of biomass resources. However, the water generated in situ not only leads to the deactivation of the active sites but also triggers the rehydration side reaction of HMF, resulting in an unsatisfactory catalytic activity and selectivity. Herein, for the first time, metal–organic frameworks (MOFs) with strong Brønsted acidity and hydrophobicity were prepared by grafting arenesulfonic acid by a diazo method. These functionalized MOFs have a large specific surface area of 1700–2600 m2/g, a high acid density of over 1.2 mmol/g, and a strong hydrophobicity with an H2O contact angle of greater than 125°. Compared with the MOF directly functionalized with sulfonic acid, the arenesulfonic acid-functionalized MOFs, which have a stronger hydrophobicity, exhibit higher activity and selectivity (up to 98.3% yield) in the transformation of fructose to HMF. Meanwhile, these arenesulfonic acid-functionalized MOFs also exhibit an excellent HMF yield for glucose and inulin reactions via the cooperative catalysis of Lewis and Brønsted acids. Furthermore, the good activity and stability of the functionalized MOFs can be maintained after recycling for five runs. The successful preparation of hydrophobic acidic MOFs provides not only an efficient catalytic system for the synthesis of HMF but also a novel, efficient route for MOF functionalization.

A 2D metal–organic framework with dual‐acidic sites for the valorization of saccharides to 5‐hydroxymethylfurfural

“…This observation is consistent with a previous report on the hydrophobic effect of aromatics between a SO 3 H group and a support, which ensures that a H 2 O solvent is repelled from the catalyst surface rather forming a layer covering the surface, thus inhibiting the rehydration side reaction. 42 2D MOF-PhSO 3 H clearly outperformed all reported catalysts, and especially for the SO 3 Hfunctionalized 3D catalysts, in terms of conversion and selectivity with a lower temperature and shorter reaction time (Table S3). 6,7,[10][11][12][13][43][44][45] A HMF yield greater than 98% has rarely been obtained for this reaction.…”

Progress in Selective Conversion of 5‐Hydroxymethylfurfural to DHMF and DMF

“…In order to make full use of biomass resource, fine chemicals, and biological liquid fuel oil can be prepared by hydrogenation, oxidation, hydrolysis, esterification, reductive depolymerisationenzymatic hydrolysis, and catalytic pyrolysis [14–26] . 5‐hydroxymethylfurfural (HMF) is a very momentous platform compound, [27–30] HMF was obtained though the dehydration of biomass‐derived carbohydrates, such as glucose, [31–35] fructose, [36–40] sucrose, [41–45] inulin, [46–50] cellobiose [51–55] and cellulose [29,56–60] . Microwave technology is a simple and efficient conversion technology that can convert biomass to HMF.…”

“…[12][13] In order to make full use of biomass resource, fine chemicals, and biological liquid fuel oil can be prepared by hydrogenation, oxidation, hydrolysis, esterification, reductive depolymerisationenzymatic hydrolysis, and catalytic pyrolysis. [14][15][16][17][18][19][20][21][22][23][24][25][26] 5-hydroxymethylfurfural (HMF) is a very momentous platform compound, [27][28][29][30] HMF was obtained though the dehydration of biomass-derived carbohydrates, such as glucose, [31][32][33][34][35] fructose, [36][37][38][39][40] sucrose, [41][42][43][44][45] inulin, [46][47][48][49][50] cellobiose [51][52][53][54][55] and cellulose. [29,[56][57][58]…”

Hierarchical Porous Nitrogen-Doped Carbon Catalyst by the Pickering HIPE Technique: Synthesis and Application in HMF Production

“…Fructose was an intermediate product of glucose chemical conversion to HMF. 47 For evaluating the function of acidic and basic sites in every step of the reaction, porous carbonaceous catalysts with only acidic or basic sites were also prepared. As shown in Figure 8a, first, the catalytic reaction with fructose as a substrate was carried out; 42.2% HMF yield could be obtained without adding any catalyst, indicating that fructose is easily dehydrated to produce HMF in the catalytic system.…”

“…Fructose was an intermediate product of glucose chemical conversion to HMF . For evaluating the function of acidic and basic sites in every step of the reaction, porous carbonaceous catalysts with only acidic or basic sites were also prepared.…”