2026-10-12T17:05:41Z https://www.scidb.cn/oai

10.57760/sciencedb.j00124.00314 2025-11-30T21:10:51Z

2025-11-30 Mechanistic Insights into Alkaline Earth Metal Ion-Catalyzed Pyrolysis of Lignin Monomers: Pathways to CO and CO2 Evolution doi:10.57760/sciencedb.j00124.00314 en  In this study, sixteen types of lignin monomer model compounds with aldehyde and carboxyl substituents at the Cα or Cβ positions were selected, representing phenyl, p-hydroxyphenyl, guaiacyl, and syringyl structural units. The catalytic effects of alkaline earth metal ions (Ca2+ and Mg2+) on the formation of CO and CO2 during lignin pyrolysis were investigated by using density functional theory (DFT) calculations. The results revealed that Ca2+ and Mg2+ readily coordinate with oxygen-containing functional groups in lignin model compounds, forming stable complexes with lower energy states. When aldehyde, carboxyl, phenolic hydroxyl, and methoxy groups coexist, the optimal binding sites for Ca2+ and Mg2+ are O(phenolic hydroxyl)–Ca2+/Mg2+–O(methoxyl) configurations. During the pyrolysis process of lignin monomers, Ca2+ and Mg2+ selectively promote the decarbonylation of benzaldehyde-type and phenylethanal-type lignin monomer model compounds (excluding phenylethanal and 4-hydroxyphenylethanal), thereby enhancing the generation of CO. Conversely, except for the Ca2+-catalyzed decarboxylation of 4-hydroxy-3-methoxyphenylethanoic acid, Ca2+ and Mg2+ can suppress the decarboxylation of benzoic acid-type and phenylacetic acid-type lignin monomer model compounds, resulting in the reduction of CO2 formation. lignin; alkaline earth metal ions; catalytic pyrolysis; density functional theory Jiang Xiaoyan Han Yiming Li Xingwei Tang Zhentao Xu Zijie Wang Qianli Hu Bin RESTRICTED dataset Science Data Bank