Encapsulated metal-based MOF nanoparticles as efficient catalysts for catalytic transfer hydrodeoxygenation of lignin-derived vanillin to 2-methoxy-4-methylphenol

Abstract

A range of carbon-encapsulated non-precious metal catalysts (Ni@C, Ce@C, Mo@C, and Zn@C) were prepared using the hydrothermal approach for the catalytic transfer hydrodeoxygenation of vanillin compound derived from lignin. The catalytic efficacy was affected by the level of acid sites, catalyst durability, and the cooperation with H-donor solvents. Analysis indicated that the thin carbon layer enclosing the active sites notably improved catalytic effectiveness and thermodynamic stability compared to alternative catalysts. Notably, Ni@C demonstrated superior catalytic performance, achieving a vanillin conversion rate of 98.72 % and an 87.12 % yield of the major product 2-methoxy-4-methylphenol under specific conditions (240 ℃, 2.0 MPa N2, ethanol as a solvent, 4-hour reaction time). These findings underscore the significant potential of carbon-wrapped MOF catalysts in advancing the sustainable utilization of lignin and fostering the growth of a more eco-friendly bioeconomy.