5-Ethoxymethylfurfural (EMF) can be considered as a potential biofuel because of its excellent combustion properties, such as high energy density and low carbon smoke emissions. In this study, Ultra-stable Y (USY) zeolite was modified with NH4H2PO4 and then used as an efficient solid catalyst for the catalytic synthesis of EMF via ethanolysis of glucose First, the NH4H2PO4-modified USY was characterized by FT-IR, XRD, BET, and NH3-TPD. The effect of reaction temperature, reaction time, substrate concentration, and catalyst loading on the yield of EMF was investigated. The P0.2-USY optimal EMF yield was 39.6 mol%, which increased by 20.7% compared to USY, and still had better activity after being reused for 5 cycles. Moreover, the pseudo-homogeneous first-order kinetics model was developed to elucidate the kinetics of EMF formation from glucose, and the kinetics results showed that the activation energy of EMF formation (64.2 kJ⋅mol-1) was lower than that of humins formation (73.2 kJ⋅mol-1). Finally, the ethanolysis pathway was proposed based on the product distribution.

The reaction characteristics and mechanism of carbohydrates is important in exploring and developing suitable technology for biofuels and biochemical production from lignocellulosic biomass. In this study, experiments combined with density functional theory (DFT) calculation and molecular dynamics (MD) simulation were used to investigate the glucose alcoholysis reaction mechanism catalyzed by extremely low concentrated sulfuric acid. The effects of temperature and tetrahydrofuran (THF) on the distribution of the product in the alcoholysis process of high‐concentration glucose were investigated. DFT calculation results showed that the addition of THF in ethanol can decrease the energy barrier of glucose degradation. Meanwhile, the MD simulation indicated that the catalyst tends to localize more around the glucose molecular, which was beneficial to the glucose degradation in ethanol. Combining the experimental and theoretical results, plausible glucose alcoholysis reaction pathways were proposed in this work. It was found that when temperature was lower than 190°C, the three main pathways were glucose conversion into ethyl glucoside (EDGP); glucose conversion into 1,6‐anhydro‐β‐d‐glucopyranose (LG), then further to levoglucosone (LGO), furans, or 1,4:3,6‐dianhydro‐α‐d‐glucopyranose (DGP); and glucose conversion to fructose. However, at higher temperatures (190 and 220°C), the main reaction pathways were, glucose conversion into LG, LGO, and ethyl levulinate (EL); glucose conversion into fructose, 5‐hydroxymethylfurfural (HMF), 5‐ethoxymethylfurfural (EMF), and EL; and glucose conversion into humins. DFT, MD simulation, and experimental results showed that the addition of THF is beneficial for the EDGP formation from high concentration glucose catalyzed by Brønsted acid.