A theoretical study on the mechanism of xylobiose during pyrolysis process

作者：Li, Zeyu; Liu, Chao^*; Xu, Xiaoxiao; Li, Qibin

来源：Computational and Theoretical Chemistry, 2017, 1117: 130-140.

DOI：10.1016/j.comptc.2017.08.014

• Xylobiose
• Density functional theory
• Reaction kinetics
• Biodegradation

In order to better understand the pyrolysis behavior of hemicellulose and unveil pyrolytic products distribution at molecular level, xylobiose was selected as a model compound of hemicellulose and relevant degradation processes were theoretically investigated by employing density functional theory (DFT) method. Several important reaction routes including directly bond breaking, Retro-Aldol reaction and Retro-Diels-Alder mechanism were analyzed, and the influence from adjacent xylose on the pyrolytic mechanism of xylobiose was interpreted systematically. The results indicate that the ring -opening of xylose unit dominates in the initial stage, followed by the cleavage of beta-1,4 -glycosides bond. Retro-Aldol reaction is kinetically favored and therefore leads to the formation of glycolaldehyde. Furfural, on the other hand, is generated via the cleavage of C1-O bond and subsequent ring forming between C2 and C5, which has a lower reaction energy barrier than that of 1-hydroxy-2-propanone. Aldehyde prefers to generate via Retro-Aldol reaction and decarbonylation. Although dehydration reaction is hard to occur in the initial pyrolysis process, it is still the major reaction channel to obtain formaldehyde and 1-hydroxy-2-propanone.

• 出版日期2017-10-1
• 单位重庆大学