Efficient catalysis of hydrodeoxygenation of lignin derivatives in aqueous phase using CoNi supported on defect MOF catalysts

The development of highly active catalysts and catalytic systems is crucial for the efficient valorization of lignin biomass. In this paper, a defective CoNi bimetallic MOF-303 catalyst was synthesized by adjusting the thermal reduction temperature and bimetallic ratio, demonstrating efficient catalytic performance in the aqueous-phase hydrodeoxygenation (HDO) of vanillin to produce 2-methoxy-4-methylphenol (MMP). Under mild conditions (200 °C, 2 h, 0.5 MPa H 2 ), the Co 2 Ni 1 /M 460 catalyst achieves complete conversion of vanillin with an MMP yield of 90.42 %. Additionally, the catalyst exhibited high activity in the aqueous-phase HDO of lignin and other lignin-derived/model compounds. Remarkably, facilitated the depolymerization of lignin into low-molecular-weight aromatic compounds, predominantly MMP, via secondary catalysis (8 h). Characterization analyses revealed that the high activity of Co 2 Ni 1 /M 460 stems not only from its defect-induced large pores, which enhance substrate adsorption and active site availability, but also from the synergistic effects between the CoNi alloy and the MOF-303 framework (Co-N interaction), promoting C=O group activation and efficient HDO. This work presents a viable strategy for designing sustainable and efficient lignin catalytic systems, highlighting the promising catalytic potential of MOF-303.