Nickel-based catalyst prepared by EDTA-assisted impregnation method and used for reduction depolymerization of lignin

The invention relates to a nickel-based catalyst suitable for catalytic reduction conversion of lignin and a preparation method of the nickel-based catalyst. According to the catalyst, metal Ni is used as an active component, and mesoporous gamma-Al2O4 is used as a carrier. The active component Ni accounts for 5-35% of the mass of the catalyst. The NiE/MA catalyst is prepared by impregnating a Ni(EDTA) anion complex on a mesoporous alumina (MA) carrier with positive charges on the surface. Compared with a Ni/MA catalyst prepared by a conventional impregnation method, the nickel crystal grain dispersity on the reduced NiE/MA catalyst is higher, and a quite thin microporous carbon shell is formed on the surface of the catalyst particle. In the preparation process, an EDTA ligand is introduced, so that the distribution of 4-propyl guaiacol hydrogenation products is remarkably influenced. The catalyst still keeps relatively good stability after being circulated for five times. For catalytic reduction depolyme