Efficient conversion of lignin to alkylphenols over highly stable inverse spinel MnFe2O4 catalysts

The aromatic properties of lignin make it a promising source of valuable chemicals and fuels. Developing efficient and stable catalysts to effectively convert lignin into high-value chemicals is challenging. In this work, MnFe2O4 spinel catalysts with oxygen-rich vacancies and porous distribution were synthesized by a simple solvothermal process and used to catalyze the depolymerization of lignin in an isopropanol solvent system. The specific surface area was 110.5 m(2)center dot g(-1), which substantially increased the active sites for lignin depolymerization compared to Fe3O4. The conversion of lignin reached 94%, and the selectivity of alkylphenols exceeded 90% after 5 h at 250 ?. Underpinned by characterizations, products, and density functional theory analysis, the results showed that the catalytic performance of MnFe2O4 was attributed to the composition of Mn and Fe with strong Mn-O-Fe synergy. In addition, the cycling experiments and characterization showed that the depolymerized lignin on MnFe2O4 has excellent cycling stability. Thus, our work provides valuable insights into the mechanism of lignin catalytic depolymerization and paves the way for the industrial-scale application of this process.

Automated summary

In this study, MnFe2O4 spinel catalysts with oxygen-rich vacancies and porous distribution were synthesized and used for lignin depolymerization. The catalytic performance of MnFe2O4 was attributed to the composition of Mn and Fe with strong synergy. The conversion of lignin reached 94%, and the selectivity of alkylphenols exceeded 90% after 5 hours.