Theoretical investigation on the carbon sources and orientations of the aldehyde group of furfural in the pyrolysis of glucose

摘要

Furfural (FF) is a valuable and characteristic product of glucose pyrolysis, but little attention has been focused on its formation mechanism. In this study, density functional theory (DFT) methods were employed to investigate the possible pathways leading to the formation of FF from glucose. The results indicate that the pyrolysis of hydroxymethyl furfural (HMF) to FF is hardly to occur duo to the high activation energy (86.3 kcal/mol) required. The dominant FF formation pathway is Path-B2 which involves the 3-deoxy-glucose (3-DG) intermediate with overall energy barrier of 87.2 kcal/mol. The major proportions of FF are derived from C-1-C-5 of glucose and the aldehyde group in FF formed at C-1 is dominant over that at C-5. FF involving the C-2-C-6 of glucose, which include two orientations (C-2 and C-6) of the aldehyde group only account for a minor proportion. (C) 2016 Elsevier B.V. All rights reserved.