Functionalized silica nanoparticles for conversion of fructose to 5-hydroxymethylfurfural

Efficient conversion of fructose to 5‐hydroxymethylfurfural by functionalized γ‐Al2O3 beads

“…As the grafted alkyl chain length increases, the ‐CH 2 vibrational bands at approximately 2928 and 2846 cm −1 became strong, and –SO 3 H groups vibrational bands at 1170 cm −1 and 1098 cm −1 decreased. Yang considered that the phenomenon was caused by steric hindrance in the structure, the longer alkyl chain grafted to the γ‐Al 2 O 3 beads, the greater steric hindrance for grafting of organic –SO 3 H groups . This experimental result was also in agreement with that of pore distribution, i.e.…”

“…Compared with Yang's research, the optimal amount of catalyst was reduced in this catalytic system. The ratio of fructose to catalyst was 50 mg:28 mg in Yang's study, while our ratio of fructose to catalyst was 90 mg:30 mg.…”

“…But the yields of 5‐HMF obtained with SO 3 H‐γ‐Al 2 O 3 –650°C, C 3 ‐SO 3 H‐γ‐Al 2 O 3 –650°C, C 8 ‐SO 3 H‐γ‐Al 2 O 3 –650°C and C 16 ‐SO 3 H‐γ‐Al 2 O 3 –650°C were 52%, 66%, 70% and 84%, respectively, which indicates that the hydrophobic properties of the functionalized γ‐Al 2 O 3 beads could increase the yield of 5‐HMF, the stronger the hydrophobicity the higher the yield of 5‐HMF. This reaction further confirmed that hydrophobic groups in the γ‐Al 2 O 3 beads can effectively isolate ‐SO 3 H groups with H 2 O molecules, hindering the progression of 5‐HMF rehydration, which was also consistent with Yang's research …”

“…The synthetic method of functionalized alumina beads was on the basis of previous research . A mixture of 14 mL ultrapure water, 100 mL absolute ethanol and 8.1 mL ammonium hydroxide was stirred at 40°C for 10 min.…”

“…Recently, Yang et al . ingeniously designed a series of hydrophobic silica nanoparticle catalysts, which also successfully restrained the rehydration of 5‐HMF in the DMSO–water solvent system, thereby improving the 5‐HMF yield and selectivity …”