Further Revealing Reaction Mechanism on the Oxidation Behavior of the Lignin Model Molecules

It is urgent to further study the mechanism of the oxidation process of biomass energy. Theoretical investigation on the oxidation of p-hydroxybenzyl alcohol (HOL), vanillyl alcohol (VOL) and syringic alcohol (SOL) at the atomic and molecular levels is completed by density function theory (DFT). The oxidative reaction mechanism is further revealed and the oxidation reaction pathway on phenolic hydroxyl group site was identified in detail. The potential energy surface information of fifteen possible reaction channels at B3LYP/6-311 + G(d,p) level was obtained. The influence of substituent effects on the oxidative reaction energy barrier has been estimated. Theoretical calculation results showed that the reactivity of phenolic hydroxyl group is stronger than methoxyl group and hydroxymethyl group. The oxidative reaction energy barrier decreases with increasing of the methoxyl group number. The elucidation of the oxidation mechanism provides a novel perspective for the study of catalytic oxidation in lignin model materials.