2,5 Hexanedione is produced from cellulose using ZrW in the presence of hydrogen while lactic acid is the main product in helium atmosphere. FTIR and kinetics studies strengthened the proposed mechanism which involves important elementary steps, namely hydroxyls abstractions and hydride transfers promoted by the Lewis acid sites of ZrW. Moreover the important increase in cellulose conversion in the presence of ZrW in hydrogen atmosphere was explained by the likely formation of additional Bronsted acid sites formed by hydrogen interacting with ZrW which catalyze the protolysis of the glycosidic bonds in cooperation with the pool of hydroxonium ions provided by the self-protolysis of water at 190 degrees C. (C) 2015 Elsevier B.V. All rights reserved.