Catalytic conversion of glucose to 5-hydroxymethylfurfural over nano-sized mesoporous Al2O3–B2O3 solid acids

• Nano-sized mesoporous Al2O3–B2O3 catalysts exhibit considerable Lewis acid sites.
• Al2O3–B2O3 catalysts can efficiently promote transformation of glucose to HMF.
• Al2O3–B2O3 catalysts take on favorable reusability.

A series of nano-sized mesoporous Al2O3–B2O3 catalysts with different molar ratios of Al/B were prepared from aluminum isopropoxide and boric acid through an evaporation-induced self-assembly (EISA) process, and were characterized by ICP-AES, FTIR (pyridine adsorption), XRD, NH3-TPD, SEM, TEM, and N2 adsorption–desorption. These catalysts were further used as solid acids in the catalytic conversion of glucose to 5-hydroxymethylfurfural (HMF). An optimized HMF yield of 41.4% was obtained within 120 min at 140 °C over Al2O3–B2O3 (Al/B = 5:5). It was demonstrated that catalysts with the presence of Lewis acid sites were more favorable for the formation of HMF.