Zhou Tingting, Zhang Hailin, Shi Junyou
Key Laboratory of Biomass Materials Science and Technology of Jilin Province, Beihua University, Binjiang East Road, Jilin City, Jilin Province, PR China.
Key Laboratory of Biomass Materials Science and Technology of Jilin Province, Beihua University, Binjiang East Road, Jilin City, Jilin Province, PR China; Collaborative Innovation Center of Forest Biomass Green Manufacturing of Jilin Province, Beihua University, Binjiang East Road, Jilin City, Jilin Province, PR China; Key Laboratory of Wooden Materials Science and Engineering of Jilin Province, Beihua University, Binjiang East Road, Jilin City, Jilin Province, PR China.
Int J Biol Macromol. 2025 Apr;299:139644. doi: 10.1016/j.ijbiomac.2025.139644. Epub 2025 Jan 20.
Lignin, as the largest renewable aromatic resource, has significant opportunities for producing high-value products via catalytic depolymerization. However, its complex structure and stable chemical bonds present challenges to its transformation. This study explores the catalytic depolymerization of lignin to aromatic monomers by means of Dawson-type phosphomolybdovanadate polyoxometalates (POMs), understanding the underlying mechanisms. Furthermore, vanadium modification is employed to adjust the catalyst's oxidative and acidic properties, demonstrating that the vanadium content in Dawson-type POMs greatly influences monomer yield. The highest yield is achieved with HPMoVO (V2). Optimal conditions include a reaction temperature of 150 °C, 4 h, an oxygen pressure of 1 MPa, a methanol-to-water ratio of 8:2, and a mass ratio of the catalyst to the wood powder being 1:1, which leads to a total yield of aromatic monomers at 24 %. POMs with high REDOX potential selectively oxidizes benzyl hydroxyl groups in lignin to benzyl carbonyl groups under the combined action of acidity and oxidation of polyacids. This weakens the βO4 bond and promotes CO bond cleavage. This approach, utilizing the tunable oxidative acidity of polyoxometalates to degrade lignin and produce various aromatic monomers, shows promising potential for lignin valorization and advancing a bio-economy based on lignocellulosic resources.
木质素作为最大的可再生芳香资源，通过催化解聚生产高价值产品具有重大机遇。然而，其复杂的结构和稳定的化学键对其转化提出了挑战。本研究探索了利用道森型磷钼钒酸盐多金属氧酸盐（POMs）将木质素催化解聚为芳香单体的方法，并了解其潜在机制。此外，采用钒改性来调节催化剂的氧化和酸性性质，结果表明道森型POMs中的钒含量对单体产率有很大影响。HPMoVO（V2）的产率最高。最佳条件包括反应温度150℃、反应4小时、氧气压力1MPa、甲醇与水的比例为8:2以及催化剂与木粉的质量比为1:1，在此条件下芳香单体的总产率为24%。具有高氧化还原电位的POMs在多元酸的酸性和氧化作用共同作用下，选择性地将木质素中的苄基羟基氧化为苄基羰基。这削弱了β-O-4键并促进了C-O键的断裂。这种利用多金属氧酸盐可调节的氧化酸性来降解木质素并生产各种芳香单体的方法，在木质素增值和推动基于木质纤维素资源的生物经济方面显示出有前景的潜力。
