Conversion of cellulose to 2,5-hexanedione using tungstated zirconia in hydrogen atmosphere
نویسندگان
چکیده
2,5 hexadione 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 as important elementary steps hydroxyls abstractions and hydride transfers promoted by the Lewis acid sites of ZrW. Moreover the important increase of 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°C.
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[1] Masotto C, Bisiani C, Camisasca C, Fusi R, Ricciardi S, Fonzi N, et al. Effects of acute n-hexane and 2,5-hexanedione treatment on the striatal dopaminergic system in mice. J Neural Transm Suppl 1995;45:281–5. [2] Wang QS, Hou LY, Zhang CL, Song FY, Xie KQ. Changes of cytoskeletal proteins in nerve tissues and serum of rats treated with 2,5-hexanedione. Toxicology 2008;244:166–78. [3] Tuckw...
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