为揭示热解过程中木质素中 α-O-4 连接键的解聚机理，运用密度泛函理论模拟了 α-O-4 型木质素二聚体模化物苯酚基甘油-α-苯基醚在 773K、101 kPa 条件下的热解行为． 通过对各步反应热力学焓变的计算，明确了二聚体的初次裂解是 C_α —O 键和 C_α —C_β键的断裂． 根据热力学可能性，将二聚体的后续裂解设计成不同的路径，热解的最终产物有小分子化合物(甲醇、乙醇、乙二醇和环氧乙烷)、苯酚及其对位取代物(对甲基苯酚、对乙基苯酚和对羟基苯甲醇)、苯及其取代物(苯甲醇)，酚类产物中较优先的是对甲基苯酚、对乙基苯酚，其次是苯酚． 此外，还将 α-O-4 型二聚体的热解行为与 β-O-4 型二聚体进行了比较，发现其不同均源于两者结构的差异．

In order to reveal the depolymerization mechanism of α-O-4 linkages in lignin during the process of py-rolysis，phenolglycerol-α-phenyl ether is selected as the α-O-4 lignin dimer mold compound，and its pyrolysis behaviors at 773K and 101kPa are simulated according to the density functional theory (DFT)． Then，the enthalpy changes of each step are calculated． It is found that the dimer pyrolysis starts from the dissociations of C_α —O and C_α —C_β bonds． According to the thermodynamics possibility，the following pyrolysis is designed into differentpaths，and the final pyrolytic products are found to contain small molecule compounds (methanol，ethanol，ethylene glycol and ethylene oxide)，phenol and para-substituted phenols (p-methyl phenol，p-ethyl phenol and p-hydroxybenzyl alcohol)，benzene and substituted benzene (benzyl alcohol)． In all these phenolic compounds，p-methyl phenol and p-ethyl phenol are the most possible products，which are followed by phenol． In addition，the pyrolysis behaviors of α-O-4 and β-O-4 lignin dimers are compared． The results show that all the differences between the two lignin dimers are attributed to their different structures．