Catalytic in-situ hydrogenation of 5-hydroxymethylfurfural (HMF) to 2,5-dimethylfuran (DMF) has received a great interest in recent years. Different reaction parameters such as catalysts, reaction temperature, time, pressure, solvents and catalyst amount optimized to achieve the highest conversion of HMF and selectivity of the products. The highest conversion of HMF (98%) and selectivity of DMF (97%) were achieved with Ru/ZSM-5 catalyst at 180 degrees C under ethanol solvent system for 3 h in 250 psi H-2. The high catalytic efficiency was attributed to the oxophilic nature and acidity of catalyst, whereas the selectivity towards DMF was attributed to the Bronsted acidity of Ru/ZSM-5 and its affinity towards the C-O bond. The catalyst exhibited high yield of DMF from in situ hydrogenation of HMF with ethanol as economical hydrogen donor. Reaction mechanism studies revealed that Ru/ZSM-5 is promoting in situ H-2 production from ethanol. Catalyst recyclability on HMF conversion and DMF selectivity has examined. (C) 2020 Elsevier Ltd. All rights reserved.