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Abstract An Al3+-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. Graphical abstract Unlabelled Image Highlights • An Al3+ modified PHSA-formaldehyde resin acid was successfully prepared. • Introducing Al3+ into PHSA-formaldehyde resin improved its texture properties. • Al3+ modified resin exhibited better performance for glucose-HMF conversion. • An optimal HMF yield of 47.4% was obtained at 170 °C for 2.0 h in GVL/H 2 O. [ABSTRACT FROM AUTHOR]

Molten salt hydrates (MSHs) are remarkable in breaking through the recalcitrant structure of microcrystalline cellulose and raw biomass. After being pretreated in 60 wt% LiBr at 130 °C for 2 h, cellulose crystallinity as well as degree of polymerization (DP) decreased. It was found that 91.3% yield of pretreated cellulose was removed from MSHs by filteration followed by being hydrolyzed into glucose with a high yield of 75.3% by dilute acid under mild reaction conditions. The pretreatment process also works on raw corn stover hydrolysis. After being pretreated at 100 °C for 5 h, 88.4% yield of cellulose in biomass was recovered and can be hydrolyzed into 54.9% yield of glucose with dilute acid. It was found that the cellulose in corn stover can be easier degraded compared with microcrystalline cellulose during MSHs pretreatment, which dues to the formation of acetic acid from hemicellulose hydrolysis. The proposed pretreatment technique presents a promising potential for glucose production from biomass in a commercial way. Unlabelled Image • MSHs pretreatment effectively decreased cellulose crystallinity and DP. • After being pretreated at 130°C for 2 h, 91.3% of cellulose was removed from MSHs via filtration. • Enhanced glucose yield of 75.3% was obtained from pretreated cellulose hydrolysis at mild condition. • 88.4% cellulose recovery and 54.9% glucose yield were obtained from MSHs pretreatment and hydrolysis, respectively. [ABSTRACT FROM AUTHOR]