Highly selective decarbonylation of 5-hydroxymethylfurfural (HMF) to furfuryl alcohol (FOL) was originally realized by adding water to organic solvent. Side reactions such as hydrogenolysis, dehydrogenation and etherification could be effectively suppressed by introducing appropriate amount of water in pure organic solvent. Based on DFT calculations, hydrogen bonds between hydroxymethyl groups and water hinder the dehydrogenation of FOL to furfural (FAL) and furan. On the other hand, in situ water-pyridineFTIR measurements revealed that the hydrogen bonding interaction between water and the hydroxyl groups on [y-Al2O3 surface decrease the acidity of Pd/Al(2)O(3)and suppresses side reactions such as hydrogenolysis and etherification. Therefore, adding water to organic solvent could be a strategy for the protection of hydroxyl groups. (C) 2017 Elsevier B.V. All rights reserved.