碱土金属离子Ca^(2+)和Mg^(2+)催化木质素二聚体热解过程的机理研究  

Theoretical study on the pyrolysis mechanism of the lignin dimer model compound catalyzed by alkaline earth metal ions Ca^(2+) and Mg^(2+)

作　　者：蒋晓燕 李一鸣 汤溧 杜晓娇 代兰花 胡斌[2] JIANG Xiaoyan;LI Yiming;TANG Li;DU Xiaojiao;DAI Lanhua;HU Bin(School of Photoelectric Engineering,Changzhou Institute of Technology,Changzhou 213032,China;National Engineering Research Center of New Energy Power Generation,North China Electric Power University,Beijing 102206,China)

机构地区：[1]常州工学院光电工程学院,江苏常州213032 [2]华北电力大学新能源发电国家工程研究中心,北京102206

出　　处：《燃料化学学报（中英文）》2024年第7期959-966,共8页Journal of Fuel Chemistry and Technology

基　　金：supported by National Natural Science Foundation of China(52206232);Jiangsu Agricultural Science and Technology Innovation Fund(CX(23)3049);Key University Science Research Project of Jiangsu province(21KJA610001).

摘　　要：本研究采用密度泛函理论方法,对碱土金属离子(Ca^(2+)、Mg^(2+))作用下的β-O-4型木质素二聚体模型化合物(2-[2-(4-甲氧基苯基)乙氧基]-苯甲醚,mc)的热解反应路径进行了理论计算。计算结果表明,Ca^(2+)和Mg^(2+)会与木质素二聚体模型化合物mc的Cβ位氧原子及甲氧基上的氧原子结合形成稳定的复合物,从而影响C_(α)−C_(β)和Cβ−O的键长和热解反应能垒。在热解过程中,Ca^(2+)和Mg^(2+)会促进协同断裂反应的发生,从而促进产物1-甲氧基-4-乙烯基苯、2-甲氧基苯酚和邻苯二酚的生成;抑制C_(α)−C_(β)键和Cβ−O键的均裂反应,从而抑制产物1-乙基-4-甲氧基苯、2-羟基苯甲醛的生成。It is essential to investigate the influence of alkaline earth metals on the pyrolysis mechanism and resulting products of lignin to enhance the efficient thermochemical conversion and utilization of lignin or biomass.In this study,the density functional theory method was used to simulate the pyrolytic reaction pathways of a β-O-4 type lignin dimer model compound(1-methoxy-2-(4-methoxyphenethoxy)benzene,mc)affected by alkaline earth metal ions Ca^(2+) and Mg^(2+).The computational findings suggest that Ca^(2+) and Mg^(2+)tend to combine with the oxygen atom at the C_(β) position and the oxygen atom on the methoxy group of the lignin dimer model compound,forming stable complexes that modify the bond lengths of the C_(α)–C_(β) and C_(β)–O bonds and affect their pyrolysis energy barriers.During the catalytic pyrolysis process,the presence of Ca^(2+) and Mg^(2+) can promote the concerted decomposition reaction,leading to increased production of products like 1-methoxy-4-vinylbenzene,2-methoxyphenol and catechol.Meanwhile,they can suppress homolytic cleavage reactions of the C_(β)–O and C_(α)–C_(β)bonds,thereby hindering the formation of other products such as 1-ethyl-4-methoxybenzene and 2-hydroxybenzaldehyde.

关 键 词：碱土金属离子 木质素二聚体 β-O-4连接 热解机理 密度泛函理论 

分 类 号：TK6[动力工程及工程热物理—生物能]