Hydrodeoxygenation of lignin-derived bio-oil over NiMn/NC catalyst for bio-based liquid fuel

Bio-oil derived from the lignin with natural aromatic structures requires deoxygenation to serve as a petroleum fuel substitute. However, the traditional bio-oil hydrodeoxygenation (HDO) process encounters challenges such as the use of high-pressure H₂, and precious metal catalysts. In this work, we investigated the effect of NiMn/NC catalyst on the in-situ HDO performance of guaiacol, a commonly used lignin oil model compound. The results indicate that 95.44% conversion of guaiacol and 81.89% deoxygenation products selectivity (cyclohexanol and cyclohexane) can be achieved at 150°C with a water/isopropanol system. During the HDO of real lignin oil, the upgraded oil product achieved a yield of 14.32 wt%, with a high H/C ratio (1.71%). Analysis of the mechanism suggests that the in-situ HDO reaction of substrate is synergistically promoted by the high surface area and weak acidic sites of the carbon support and nickel-oxygen vacancy interface. This work presents an advanced strategy for the in-situ HDO of bio-oil into bio-based liquid fuel by nickel-based catalysts.