▎ 摘　　要

NOVELTY - Lignin depolymerization catalyst comprises a support comprising carbon nitride; and a transition metal bonded to a nitrogen functional group of the support, where the transition metal is included in an amount of 0.1-1 wt.% based on the total weight of the lignin depolymerization catalyst. USE - The lignin depolymerization catalyst is useful for producing lignin-derived aromatic monomer (claimed) in paper industry. ADVANTAGE - The method produces a high yield of lignin aromatic monomer directly from lignocellulosic biomass using catalyst supported with a very low content of transition metal, so that it is possible to separate lignin and recover holocellulose more economically than conventional techniques. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: preparing lignin depolymerization catalyst, comprising preparing a mixture by dissolving transition metal in a solvent, and mixing with support, and calcining the solid formed by evaporating the solvent of the mixture; and producing lignin-derived aromatic monomer, comprising introducing lignin depolymerization catalyst, lignocellulosic biomass material, and methanol solution containing support and transition metal impregnated in the support into a reactor, and converting lignin of lignocellulosic biomass material into an aromatic monomer by increasing the temperature and pressure inside the reactor.