Coupled acid and base UiO-66-type MOFs supported on g-C3N4 as a bi-functional catalyst for one-pot production of 5-HMF from glucose

Tuning of Selectivity for Sustainable Production of Acrolein from Glycerol

“…[65][66][67] It should be noted that these materials are actively used in the dehydration of C 5 À C 6 sugars into platform chemicals such as furfural and 5-hydroxymethylfurfural (HMF). [68][69][70][71][72][73] Table 2 represents comparison of various MOFs activity and selectivity in the dehydration of xylose and glucose as well as glycerol. Despite the fact that it was possible to achieve excellent results using MOF-808 as a catalyst for the dehydration of glycerol, this material is stable only for 10 h. At the same time, MOF catalysts are stable in catalytic dehydration of C 5 À C 6 sugars up to 10 cycles.…”

Tuning Brønsted and Lewis acidity on phosphated titanium dioxides for efficient conversion of glucose to 5-hydroxymethylfurfural

“…They reported that the reaction carried out at 130 C for 4 h can produce the HMF yield of 76% and selectivity of 85%. 16 Several other bifunctional solid catalysts including metal phosphates, 17,18 metal sulfates, [19][20][21] mixed metal oxides, 22,23 metal-supported catalysts, 24,25 MOFs, 26,27 and heteropolyacids, 28,29 were also examined for the HMF production from hexose sugar. Despite their efficient HMF production, the synthesis of these catalysts is rather complicated, generates a large amount of waste, and requires high production expense.…”

Microporous and mesoporous structure catalysts for the production of 5‐hydroxymethylfurfural (5‐HMF)

“…80 Besides, the TG analysis showed the catalyst has high thermal stability, as the catalyst can withstand high temperatures. 80 Zhang et al 81 also reported PDA modification with polyurethane (PU) to synthesize novel multifunctional MOFs, UiO-66-SO 3 H-NH 2 /PDA@PU, by tuning the ratio of the organic ligand of monosodium 2-sulfoterephthalate and 2-aminoterephthalic, which create suitable acid-base bifunctional sites. As a result, the use of UiO-66-SO 3 H-NH 2 /PDA@PU catalyst produced a 70.3% yield of HMF compared to only 56.6% HMF yield produced by UiO-66-SO 3 H/PDA@PU.…”

“…78 Furthermore, adding metal functionality centers and organic ligands can create multi-functional heterogeneous catalytic reactions that contain one or more thermally stable active sites for the HMF conversion. 78,79 A chemically functionalized microporous MOF, polydopamine modified g-C 3 N 4 (C 3 N 4 @PDA) supported on UiO-66-type MOFs was successfully synthesized via one-pot modulated hydrothermal method by Zhang et al, 80 as they prepared few different types of the catalyst by loading the UiO-66-type MOFs with only acid, base, or acid-base bifunctional active sites through the combination between zirconium (Zr) ions with monosodium 2-sulfoterephthalate and 2-aminoterephthalic as shown in Figure 7. As a result, the acid-base bifunctional UiO-66-NH 2 -SO 3 H-2/C 3 N 4 @PDA catalyst achieved the highest 54.9% yield of HMF in isopropanol/DMSO solvent system under the optimal condition.…”

“…As a result, the acid-base bifunctional UiO-66-NH 2 -SO 3 H-2/C 3 N 4 @PDA catalyst achieved the highest 54.9% yield of HMF in isopropanol/DMSO solvent system under the optimal condition. 80 The catalyst has a synergistic effect and good acidity and basicity value of the bifunctional active sites, which is successfully loaded onto the microscopic structure of the catalyst surface with the particle size of range between 0.2 and 0.8 μm, as shown in Figure 8, as the base and acid active sites involved in the isomerization of glucose to fructose and dehydration of fructose to HMF, respectively. 80 Besides, the TG analysis showed the catalyst has high thermal stability, as the catalyst can withstand high temperatures.…”