Lignin, an abundant renewable aromatic resource, has a complex structure composed of various C₉ propyl phenol units with cross-linked C–C, ester and ether linkages. Herein, we report a two-step process for the selective production of ethylbenzene from corncob lignin valorization. This process starts with hydrodeoxygenation of lignin to C₈ ethylcyclohexane (42%), C₉–C₁₇ cyclic alkanes (bio-jet fuel range, 38%), and some C₃–C₇ alkanes (gasoline range, 20%) over Ni/Silicalite-1 (Ni/S-1) at 300 °C and 6 MPa H₂ using a non-polar solvent. After separation by distillation, the subsequent dehydrogenation of ethylcyclohexane over Pt–Sn/Al₂O₃ leads to the formation of ethylbenzene with 99.3% yield at 500 °C and 0.5 MPa H₂ in a continuous flow reactor. It is demonstrated that the selective production of C₈ ethylcyclohexane from lignin specifically proceeds by thermal cracking and hydrogenolysis on Ni nanoparticles (NPs). The thermal cracking of lignin eliminates the C_β–C_γ bond in the side 3-C chain of the depolymerized C₉ radicals, as formed by the homolytic cleavage of β-O-4 linkages in lignin via a quinone methide reaction pathway. Additionally, Ni NPs facilitate the decarboxylation of the carbonyl groups formed from the end hydroxyl and ester groups of C₉ lignin units. The established strategy enables the selective production of value-added ethylbenzene from lignin valorization and the simultaneous formation of a qualified bicyclic alkane bio-jet fuel with high thermal stability.

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木质素向乙苯的选择性转化

木质素是一种丰富的可再生芳香资源，其结构复杂，由各种具有交联CC，酯键和醚键的C ₉丙基苯酚单元组成。在这里，我们报告了从玉米芯木质素增值选择性生产乙苯的两步过程。该过程首先将木质素加氢脱氧为C ₈乙基环己烷（42％），C ₉ -C ₁₇环状烷烃（生物喷气燃料范围，38％）和一些C ₃ -C ₇烷烃（汽油范围，20％）。使用非极性溶剂在300°C和6 MPa H ₂下的Ni / Silicalite-1（Ni / S-1）。通过蒸馏分离后，随后在Pt–Sn / Al ₂ O上将乙基环己烷脱氢_图3导致在连续流动反应器中在500℃和0.5MPa H ₂下以99.3％的产率形成乙苯。证明了通过木质素对镍纳米颗粒（NPs）的热裂解和氢解反应特别地从木质素选择性生产C ₈乙基环己烷。热木质素消除作为C裂化_β -C _γ在解聚C的侧3-C链键₉的基团，如通过在木质素β-O-4键的均裂形成经由一个醌甲基化物的反应途径。另外，Ni NPs促进了由C ₉的末端羟基和酯基形成的羰基的脱羧木质素单位。既定的策略能够从木质素增值中选择性生产增值乙苯，并同时形成具有高热稳定性的合格双环烷烃生物喷气燃料。