Efficient Ni-Cu/AC Bimetal Catalyst for Hydrogenolysis of Lignin to Produce High-Value-Added Chemicals

摘要

Efficient depolymerization of natural lignin is the key step to convert lignin to sustainable and added-value chemicals.In this paper,a carbon-supported Ni-Cu bimetallic catalyst was developed for the hydrogenation of poplar lignin and β-O-4 model compounds.Five Ni-Cu bimetallic catalysts were prepared by immobilizing Ni and Cu at fixed Ni loading(5%)and varied Cu loading(0%,5%,10%,20%,30%)on activated carbon(AC).All the Cu-Ni/AC bimetal catalysts exhibited higher catalytic activity than either Ni/AC or Cu/AC catalysts.5Ni-5Cu/AC gave the highest bio-oil yield of 40.2 wt% for the hydrogenation of.poplar lignin.The XPS,XRD,and HRTEM characterization of the catalysts showed that elemental copper and Cu-Ni alloy were formed on the surface of 5Ni-5Cu/AC catalyst,which could promote the efficient depolymerization of lignin into phenolic monomers.The possible mechanism for the lignin depolymerization was also studied and proposed based on the β-O-4 bond model compounds.This study provides a viable strategy for the conversion of lignin into added-value chemicals with low cost catalyst.