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 H-2 to phenolic compound molar ratios of similar to 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. (C) 2015 Elsevier B.V. All rights reserved.