One‐Step Approach to 2,5‐Diformylfuran from Fructose by Using a Bifunctional and Recyclable Acidic Polyoxometalate Catalyst

Abstract

A series of acidic cesium salts of molybdovanadophosphoric heteropolyacids (CsMVP‐HPAs) are developed as bifunctional and recyclable catalysts for a one‐step approach to 2,5‐diformylfuran (DFF) from fructose with molecular oxygen as the oxidant under environmentally benign conditions. The CsMVP‐HPAs afford the direct synthesis of DFF from fructose through acidic site (H)‐promoted fructose dehydration and metallic site (V)‐catalyzed successive aerobic oxidation of 5‐hydroxymethylfurfural (HMF). The catalytic performances of CsMVP‐HPA toward fructose dehydration and HMF oxidation are related to its acid density and V content, respectively. Moreover, the increase in the V content of CsMVP‐HPA results in its decreased acid density, which suggests its converse catalytic performance toward fructose dehydration and HMF oxidation. An optimum balance between the dehydration and oxidation functions of CsMVP‐HPAs reveals that a ratio of acid density to molar concentration of V between 1.64 and 3.34 achieves a maximum yield of 60 % for DFF from fructose with Cs3HPMo11VO40 as a catalyst under atmospheric pressure of oxygen. Moreover, Cs3HPMo11VO40 behaves as a heterogeneous catalyst and can be easily reused at least for four times. This research highlights an efficient bifunctional catalyst for transforming renewables into fine chemicals in tandem reactions of dehydration and oxidation.

Fabrication of Trifunctional Polyoxometalate‐Decorated Chitosan Nanofibers for Selective Production of 2,5‐Diformylfuran

“…The selectivity to DFF was increasedf rom 73.3 to 85.5 %, which was owing to the increase in surface basicity in the chitosann anofibers. [9] Finally,t he selectivity to DFF increased as the HPMoV loading amount increased from 5t o2 5%,t hen decreasedu pon further increasing the HPMoV amount to 35 %. The relationship between the activity of HPMoV/CS-f(n)a nd the HPMoV loading amount on the chitosann anofibers was also studied.…”

“…Electrospinning has been recognized as an efficient technique for fabrication of chitosan nanofibersr anging from 5t o 500 nm with amazing characteristics of very large surfacea reato-volumer atios. [6] HMF can be convertedi nto as eries of bulk chemicals and intermediates through various chemical transformationsi ncluding maleic anhydride (MA), [7] 2,5-furandi-carboxylic acid (FDCA), [8] 2,5-diformylfuran (DFF), [9] 2,5-bishydroxymethylfuran (BHMF), [10] 2,5-dihydroxymethyltetrahydrofuran (THFDM), [11] 2,5-dimethylfuran (DMF), [12] 3-hydroxymethylcyclopentanone (HCPN), and 3-hydroxymethylcyclopentanol (HCPL;S cheme S1 in the SupportingI nformation). 5-Hydroxymethylfurfural( HMF) hasd rawn increasing attention as ab io-platform chemical, [5] which can be synthesized by acid-catalyzed dehydration of carbohydrates includingm onoor polysaccharides.…”

“…DFF is av ersatile compound that can be used as ap recursori n the synthesis of functional polymers, [14] pharmaceuticals, [15] antifungal agents, [16] furan-urea resins, [17] heterocyclic ligands, [18] and other value-added products.H owever,s everal kinds of furan compounds such as FDCA, 5-formyl-2-furancarboxylic acid (FFCA), 5-hydroxymethyl-2-furancarboxylic acid (HMFCA), accompanied with DFF,c an possibly be formed during HMF oxidation. [22][23][24][25] POMs containing vanadium also show potentialf or the oxidation of HMF to give as eries of products including DFF [9] andM A: [7] Cs 3 HPMo 11 VO 40 gave 99 %c onversion and 99 %y ield of DFF at 110 8Cf or 6hin DMSO under N 2 and O 2 in ao ne-pot,t wo-stepp rocess;H 5 PMo 10 V 2 O 40 presented 100 %c onversion and 64 %y ield of MA at 90 8Cf or 8h in Trifunctional catalysts based on polyoxometalate (POM)d ecorating chitosan nanofibers (H 5 PMo 10 V 2 O 40 /chitosan nanofibers, abbreviated as HPMoV/CS-f), synthesized by using the electrospinningm ethod, realized highly efficient oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-diformylfuran (DFF).D ecorating chitosann anofibers with POMs generated enhanced catalytic activity by merging their uniquei ndividual properties of redox ability,B rønsted acidity,b asicity,a nd nanofiber structure with higher surface area. To date, both homogeneous and heterogeneous metal catalysts have been explored for the oxidation of HMF to DFF with various oxidants.…”

“…[27] Compared with HMF as the feedstock, directp roductiono fD FF from saccharides is more economical with good tolerance to feedstocks and energy release. [9] Also, Ghezali et al achieved the production of DFF directly from fructose and inulin over H (3 + n) PMo (12Àn) V n O 40 (n = 0-2) in choline chloride/DMSO solvent, for whichH 4 PMo 11 V 1 O 40 was found to be the most active, giving 84 %y ield of DFF at 120 8Cf or 6h. [28] The catalytic activity was attributed to the co-existence of Brønsted acid and redox centers.…”

Catalytic Hydrotreatment of Fatty Acid Methyl Esters to Diesel‐like Alkanes Over Hβ Zeolite‐supported Nickel Catalysts

“…[ [43][44][45] 10 wt % Ni/Hb zeolite with Si/Al = 25 showed the best performance in both deoxygenation and isomerization reactions and was thus selected for investigations on the optimal operating conditions for maximum C 15 -C 18 alkane and FAME conversions.…”