Abstract <p>This study presents the first investigation into the hydrodeoxygenation (HDO) of syringol (2,6-dimethoxyphenol) and 2-methoxyhydroquinone—model compounds for lignin depolymerization products—using in situ synthesized NiMoS nanocatalysts. The catalysts were formed from oil-soluble precursors (Mo(CO)₆ and Ni(II) 2-ethylhexanoate) and elemental sulfur. By varying the reaction conditions (300–350°C, 1–7 MPa H₂, 15–300 min, and substrate-to-Mo molar ratios of 10.5 : 1 to 105.3 : 1), product distribution can be controlled to achieve 100% conversion and high yields of deoxygenated products, primarily cyclohexane. Characterization by XRD, HR-TEM, and XPS revealed that the catalyst formed during syringol conversion consisted of highly dispersed three-layer nanoparticles (average length: 4.3 nm), dominated by MoS₂ (81.5%) and a Ni–Mo–S active mixed phase (80.4%). The proposed HDO pathway for syringol proceeds through initial demethoxylation to guaiacol and phenol, followed by their subsequent deoxygenation and hydrogenation.</p>