Nano molybdenum carbides supported on porous zeolites for Kraft lignin decomposition to aromatic monomers in ethanol

In this study, Kraft lignin was efficiently converted into aromatic monomers of arenes, aromatic alcohols, and aromatic aldehydes over nano molybdenum carbides catalysts supported on porous ZSM-22, ZSM-5, USY, Beta, and IM-5 zeolites in ethanol. The results showed that ZSM-22 exhibited the highest performance with maximum aromatic yield of 0.609 g/g Kraft lignin at 280 °C for 3 h with 20% Mo loading, and the catalytic performance over ZSM-22 retained for 4 recycling runs without obvious aromatic yield loss. The high activity over ZSM-22 zeolite is attributed to the high dispersion of β-Mo 2 C particles with more exposed active sites and enhanced accessibility of lignin to β-Mo 2 C in large pores. Aggregation of β-Mo 2 C for higher Mo loading is unfavorable for Kraft lignin decomposition. The performances over differently pretreated ZSM-22 zeolites demonstrate that large pore size and external surface areas are key factors in determining the catalytic activity .