Production of HMF from glucose using an Al3+-promoted acidic phenol-formaldehyde resin catalyst

An Al 3+ -modified formaldehyde-p-hydroxybenzenesulfonic acid resin catalyst (Al-SPFR) was synthesized through a hydrothermal method. N 2 adsorption–desorption experiment and acid–base titration revealed that the Al-SPFR catalyst had better texture properties and higher strong acid content than the previously prepared unmodified SPFR . The effects of reaction time and temperature, catalyst loading, and water content in water/GVL mixture were investigated for glucose dehydration using Al-SPFR as the catalyst. An HMF yield of 47.4% was obtained at 170 °C for 2 h in the biphasic GVL/H 2 O medium. Further performing a five-cycle experiment, the HMF yield initially decreased and then remained fairly constant, and the recyclability of the Al-SPFR was reasonable.