氮掺杂炭负载Co-V催化剂的制备及催化解聚木质素制备单酚类化合物  

Preparation of Nitrogen-Doped Carbon-Supported Co-V Catalyst for Catalystic Depolymerization of Lignin to Produce Monophenolic Compounds

作　　者：马宇乔 刘兴旺 钱勇[1] 欧阳新平[1] MA Yuqiao;LIU Xingwang;QIAN Yong;OUYANG Xinping(School of Chemistry&Chemical Engineering,South China University of Technology,Guangzhou 510640,China)

机构地区：[1]华南理工大学化学与化工学院,广东广州510640

出　　处：《能源环境保护》2025年第2期120-136,共17页Energy Environmental Protection

基　　金：国家重点研发资助项目(2022YFC2105904)。

摘　　要：木质素通过解聚为单酚类化合物进一步转化为液体燃料,被认为是化石能源的有效替代品。然而,木质素复杂的化学结构制约了其高效降解。因此,以硝酸钴、偏钒酸铵和三聚氰胺为原料,利用钒与氮的络合作用以及氮化钒的高稳定性,在无其他外加碳源的基础上制备了一种氮掺杂炭负载Co-V催化剂。优化条件下制备的Co_(1)-V_(3)/NC(30)催化剂具有较高的比表面积、孔容和分级多孔结构(包括微孔、介孔和大孔)。金属活性组分Co^(0)和V^(3+)之间的协同作用,以及氮对活性组分的锚定,促进活性组分的分散,使得制备的催化剂具有良好的催化活性和稳定性。在优化的反应条件下(180℃,0.5 MPa O_(2),8 h),Co_(1)-V_(3)/NC(30)催化剂催化氧化降解有机溶剂木质素,获得了86.3%的生物油收率和28.8%的单酚类化合物收率。借助模型物对木质素反应机理进行探究,提出了Co_(1)-V_(3)/NC(30)催化断裂木质素中Cα—Cβ键的机理。制备了高效、廉价且稳定性好的金属催化剂,并通过催化氧化的方法将木质素降解成单酚类化合物,对木质素在生物质能源上的利用方面具有较好的指导作用。Lignin,a renewable biomass component,holds promise as a fossil fuel alternative through its depolymerization into monophenolic compounds for liquid fuel production.However,its complex chemical structure presents significant challenges to efficient degradation.This study addresses this limitation by developing a nitrogen-doped carbon-supported Co-V catalyst,synthesized using cobalt nitrate hexahydrate,ammonium metavanadate,and melamine as precursors.The synthesis capitalized on vanadium-nitrogen coordination and the inherent stability of vanadium nitride,eliminating the need for an external carbon source.By regulating the mass ratio of melamine to metal salts,the structural morphology and the types and contents of Co and N in the catalyst were precisely controlled.The optimized Co_(1)-V_(3)/NC(30)catalyst exhibited abundant defect sites,a high specific surface area,large pore volume,and hierarchical porous structure comprising micropores,mesopores,and macropores.The catalyst also featured a high content of pyridinic nitrogen and metallic cobalt(Co^(0)),along with a relatively low content of Co-Nx species.Synergistic interactions between the active components Co^(0)and V^(3+),coupled with nitrogen-mediated anchoring,ensured uniform dispersion of active sites,thereby enhancing catalytic activity and stability.Under optimized reaction conditions(180℃,0.5 MPa O_(2),8 h),the catalyst achieved 86.3%bio-oil yield and 28.8%monophenolic compounds from organosolv lignin.Notably,Co_(1)-V_(3)/NC(30)outperformed commercial catalysts(Co_(1)-V_(3)/AC and Co_(1)-V_(3)/ZSM-5),demonstrating the critical role of nitrogen-doped carbon in anchoring and dispersing metal active components.2D-HSQC NMR analysis confirmed the catalyst′s exceptional activity in cleaving both C—O and C—C bonds between lignin structural units,enabling efficient degradation into monophenolic compounds.Mechanistic investigations using aβ-1 lignin model compound(diphenylethanone)revealed that the cleavage of C_(α)—C_(β)bonds proceeds via two pathway

关 键 词：木质素 催化氧化 解聚 氮掺杂炭载体 单酚类化合物 

分 类 号：X505[环境科学与工程—环境工程]