Mo₂C catalyzed vapor phase hydrodeoxygenation of lignin-derived phenolic compound mixtures to aromatics under ambient pressure

High aromatics yield (>90%, benzene and toluene) was obtained from vapor phase hydrodeoxygenation (HDO) of phenolic compound mixtures containing m-cresol, anisole, 1,2-dimethoxybenzene, and guaiacol over molybdenum carbide catalysts (Mo₂C) under atmospheric pressure at 533-553 K, even with H₂ to phenolic compound molar ratios of ∼3,300. Toluene selectivity increased proportionately (4%-66%) to m-cresol content in HDO of phenolic compound mixtures (molar composition: 0%-70%) at quantitative conversion. Phenol selectivity increased with decreasing conversion, implying that the aryl-methoxyl bond in guaiacol is cleaved first, before the aryl-hydroxyl bond. Low selectivity to cyclohexane and methylcyclohexane (<10%) across the conversions investigated (18-94%) demonstrates that undesired successive hydrogenation reactions of aromatics over Mo₂C were inhibited, presumably due to in situ oxygen modification, as inferred from titration studies of aromatic hydrogenation reactions using methanol and water as titrants.