Decomposition of Lignin Using MO–MgAlOy Mixed Oxide Catalysts (M=Co, Ni and Cu) in Supercritical Ethanol

In this study, we performed the depolymerization reaction of concentrated sulfuric acid hydrolysis lignin (CSAHL) in supercritical ethanol without supplying external hydrogen. Cu demonstrated the highest monoaromatic yield of 18.4 wt% among Co, Ni and Cu when incorporated into MgAlO_y. With increasing the amount of Cu loading, it was found that the optimum Cu loading was 30 wt%, where the number of acid sites had the maximum. In case of CuO–MgAlO_y sample with higher Cu loading than 30 wt%, the decrease in the acid sites and the significant sintering of Cu metal during reaction were observed, leading to the decline in the monoaromatic yield.