Abstract:

the sulfonic group functionalized ionic liquid--1-H-3-(3-sulfonic acid)propylimidazolium chloride was immobilized on micro-ball silica-gel using 3-chloropropyltrimethoxysilane as coupling agent to obtain the silica-gel immobilized ionic liquid(IL3). The IL3 was characterized by SEM, FTIR, TG, 13C-NMR, BET, and titration its surface acidity. Its catalytic performance in the synthesis of 5-hydroxymethylfurfural (HMF) from fructose dehydration was investigated. The results indicate that 1-H-3-(3-sulfonic acid)propylimidazolium chloride could be immobilized on micro-ball silica-gel surface, and the IL3 was a good catalyst for the HMF synthesis from fructose dehydration. The yield of HMF is up to 82.1%, using 45.4-IL3 as the catalyst, with ethylene glycol monomethyl ether(EGME) as solvent at 115℃ over 5h. The used IL3 could be reused conveniently. But the yield of HMF dropped gradually with the more times of the IL3 recycled. After the IL3 reused four times, the yield of HMF decreased from 82.1% to 53.0%.

Key words: hydroxymethylfurfural, functionalized ionic liquid, immobilization, silica-gel, fructose