Lignin shows great potential for sustainable production of high-quality fuels and value-added chemicals. The development of efficient and highly stable multifunctional catalysts for the depolymerization of lignin into aromatic chemicals remains a great challenge. In this work, environmentally friendly NiFe₂O₄ spinel catalyst characterizing with rich oxygen vacancies and porous structures was constructed by introducing Ni to modulate the coordination environment of cations in Fe₃O₄. Under optimal conditions, the conversion of alkali lignin catalyzed by NiFe₂O₄ reached 91.0%, the yield of liquid product reached 83.6% and the yield of aromatic monomer products was 31.7%. Combined results from catalyst characterization, product analysis and density functional theory calculations showed that the Lewis acidic center of the catalyst was significantly improved by the introduction of Ni, which promoted the C-O bond breaking in lignin. The Ni-O-Fe structure facilitated the adsorption of lignin substrates and reaction intermediates, which resulted in the improved depolymerization efficiency of lignin. The present work provides valuable insights into the depolymerization of lignin by spinel catalysts, and offers ideas for the future design and development of binary or even ternary spinel catalysts for the depolymerization of lignin.

木质素在可持续生产高质量燃料和增值化学品方面显示出巨大潜力。开发高效且高度稳定的多功能催化剂以将木质素解聚为芳香族化学品仍然是一个巨大的挑战。本工作通过引入Ni调节Fe ₃ O ₄中阳离子的配位环境，构建了具有丰富氧空位和多孔结构的环境友好型NiFe ₂ O ₄尖晶石催化剂。_{在最佳条件下，NiFe 2} O ₄催化碱木质素转化率达到91.0%，液体产物收率达到83.6%，芳香单体产物收率31.7%。综合催化剂表征、产物分析和密度泛函理论计算结果表明，Ni的引入显着改善了催化剂的路易斯酸性中心，促进了木质素中CO键的断裂。Ni-O-Fe结构有利于木质素底物和反应中间体的吸附，从而提高木质素的解聚效率。目前的工作为尖晶石催化剂解聚木质素提供了有价值的见解，并为未来设计和开发用于木质素解聚的二元甚至三元尖晶石催化剂提供了思路。