Efficient synthesis of 5-ethoxymethylfurfural from biomass-derived 5-hydroxymethylfurfural over sulfonated organic...

Herein, we investigated catalytic potential of a functionalized porous organic polymer bearing sulfonic acid groups (PDVTA-SO₃H) to the etherification of 5-hydroxymethylfurfural (HMF) to 5-ethoxymethylfurfural (EMF) under solvent-free conditions. The PDVTA-SO₃H material was synthesized via post-synthetic sulfonation of the porous co-polymer poly-divinylbenzene-co-triallylamine by chlorosulfonic acid. The physicochemical properties of the PDVTA-SO₃H were characterized by FT-IR, SEM, TG-DTG, and N₂ adsorption isotherm techniques. PDVTA-SO₃H had high specific surface area (591 m² g^-1) and high density of -SO₃H group (2.1 mmol g^-1). The reaction conditions were optimized via Box-Behnken response surface methodology. Under the optimized conditions, the PDVTA-SO₃H catalyst exhibited efficient catalytic activity with 99.8% HMF conversion and 87.5% EMF yield within 30 min at 110 °C. The used PDVTA-SO₃H catalyst was readily recovered by filtration and remained active in recycle runs.