Effect of Metallic Dopants for ZnO Support on Catalytic Activity for Depolymerization of Lignin

Abstract

Alkaline lignin was depolymerized with ferrite and nickle catalysts on ZnO support. The catalysts were prepared by microwave assisted impregnation method. The catalysts were characterized by X-ray diffraction spectrometer and BET (Brunauer–Emmett–Teller) surface area analyzer to confirm the structure. The amount of phenolic compounds was identified by gas chromatograph equipped with flame ionization detector (GC-FID). Main products of the reaction contain gluacal, ethylgluacal, and phenol. Fourier transform-infrared spectroscopy (FT-IR) was used to study the functional group of initial alkaline lignin and lignin residues after the reaction. It was found that at 300ºC with heating rate 10ºC/min for 1 h with alkaline lignin/solvent ratio of 1.75% (w/v), Fe-Ni bimetallic catalyst on ZnO nanoparticle support showed the highest phenolic compound yield of 2.75 wt.%.