Selective Catalytic Transfer Hydrogenation of Lignin to Alkyl Guaiacols Over NiMo/Al‐MCM‐41
Xinyu Lu, Haoquan Guo, Jiajia Chen, Duoying Wang, Adam F. Lee, Xiaoli Gu
Abstract
Abstract Efficient deoxygenation of lignin‐derived bio‐oils is central to their adoption as precursors to sustainable liquid fuels in place of current fossil resources. In‐situ catalytic transfer hydrogenation (CTH), using isopropanol and formic acid as solvent and in‐situ hydrogen sources, was demonstrated over metal‐doped and promoted MCM‐41 for the depolymerization of oxygen‐rich (35.85 wt%) lignin from Chinese fir sawdust (termed O‐lignin). A NiMo/Al‐MCM‐41 catalyst conferred an optimal lignin‐derived oil yield of 61.6 wt% with a comparatively low molecular weight ( M w =542 g mol −1 , M n =290 g mol −1 ) and H/C ratio of 1.39. High selectivity to alkyl guaiacols was attributed to efficient in‐situ hydrogen transfer from isopropanol/formic acid donors, and a synergy between surface acid sites in the Al‐doped MCM‐41 support and reducible Ni/Mo species, which improved the chemical stability and quality of the resulting lignin‐derived bio‐oils.