Adjacent acid sites cooperatively catalyze fructose to 5-hydroxymethylfurfural in a new, facile pathway

Sugar dehydration to 5-hydroxymethylfurfural in mixtures of water/[Bmim]Cl catalyzed by iron sulfate

“…10 Besides, HMF can be used to synthesize 2,5-furandicarboxylic acid, a promising monomer for the manufacture of bio-based polyethylene furanoate (with better mechanical strength and oxygen/CO2 barrier properties) to replace the petroleum-based polyethylene terephthalate. 11 In the past decades, numerous research efforts have been devoted to converting bio-based carbohydrates into HMF in various catalytic reaction systems, such as the use of catalysts (including among others mineral acid, 12,13 metal salts 14 and solid acid catalysts like HfO(PO4)2, 15 activated carbon, 16 zeolite, 17 TiO2, 18 Ta-W oxide 19 and novel mesoporous carbon 20 ), and the use of water or other organic solvents, 21,22 aqueous-organic biphasic solvent system 18,23,24 as well as sub-or supercritical systems. 25,26 Fructose, derived from the hydrolysis of biomass (rich in the cellulosic component), 27,28 is considered as a preferred starting feedstock for HMF synthesis since the furanic structures thereof make it easier to be converted with a higher selectivity towards HMF as compared to raw biomass.…”

Influence of Dimethylsulfoxide and Dioxygen in the Fructose Conversion to 5-Hydroxymethylfurfural Mediated by Glycerol's Acidic Carbon

“…These bands correspond to the asymmetric and symmetrical vibrational stretching of SO 2 , respectively (Zhao et al, 2016;Mantovani et al, 2018). The 3,370 cm −1 centered broadband is attributed to O-H stretching of -COOH groups while the band around 1,590 cm −1 can be attributed to the C=C double bond stretch characteristic of carbons (Thapa et al, 2017;Yu et al, 2020). One band at 1,701 cm −1 is characteristic of carbonyls from -COOH group and another at 2,930 cm −1 is attributed to the elongation vibrations of methylene groups (Zhao et al, 2017).…”

“…Xiong et al (2018) proposed that these groups can act by establishing hydrogen bonds with the carbohydrates tested as substrate and increasing the polarity of the carbon surface, improving its contact with the sulfonic and carboxylic groups. Recently, Yu et al (2020) showed that adjacent acid sites on carbon surface cooperatively catalyze the fructose dehydration. The adjacent Brønsted sites lead to co-interaction with the fructose, then accelerating the dehydration.…”

“…The synergistic action of sulfonic and oxygenated groups allows a better catalytic performance for the production of 5-HMF (Thapa et al, 2017). Recently, Yu et al (2020) also demonstrated that Brønsted acid sites with adjacent carboxyl present higher catalytic ability than isolated ones.…”

Effective Dehydration of Fructose Over Stable Ti-Doped SBA-15 Catalysts

“…In a typical reaction, fructose (0.1 g) was mixed with Ti-SBA-15 at different mass ratios (1:1–20:1), followed by 10 ml of DMSO. The reactor was sealed and immersed in a heated at different temperatures (110–170°C) oil bath with stirring at a speed of 500 rpm for 0.5–5 h ( Yu X et al, 2020 ). Time zero was established when the reactor was immersed in the oil bath.…”