Combination of Brønsted and Lewis Polymeric Catalysts for Efficient Conversion of Cellulose into 5-Hydroxymethylfurfural (HMF) in Ionic Liquids

Stable oil-in-water high internal phase emulsions (HIPEs) with an internal phase volume fraction of 85 % were stabilized using Tween 85. The prepared poly(HIPEs) were first investigated as adsorbents to treat water polluted with Cr III , and then the catalysts with Lewis acidic sites was synthesized. The catalysts with Brønsted acidic sites were obtained by ion-exchanging. The as-prepared HIPEs–Cr III (PEs–Cr III ) and HIPEs–SO 3 H (PEs–SO 3 H) possess open-cell structure, interconnecting pores, and strong acidity, they are utilized as highly efficient catalysts for the conversion of biomass to 5-hydroxymethylfurfural (HMF). These results showed maximum production yields for cellulose, glucose, and fructose of 37.0 %, 58.0 %, and 80.8 %, respectively. PEs–Cr III and PEs–SO 3 H can be very easily recycled at least four times without significant loss of activity. Herein, a new method is presented to transform cellulose by using two catalysts in a one-pot process for meeting the varying demands involved at different reaction stages.