Synergistic catalyst Ru/NbOPO₄/TiO₂ for selective hydrodeoxygenation of phenolics towards unlocking lignin's potential

Lignin valorization has attracted significant attention in recent years due to its abundance and potential as a renewable organic carbon resource to produce a variety of value-added chemicals and fuel additives. Catalytic upgrading of lignin faces challenges due to its complex structure and an active catalyst with selective surface properties is needed to break the stable C–O and C–C interunit linkages. In the present work, we developed a series of multifunctional Ru/NbOPO₄/TiO₂ catalysts with varying surface acidic properties and explored their potential upon hydrogenolysis of lignin model compound eugenol. Textural and surface acidic properties of the prepared materials were studied by means of different techniques such as N₂-physisorption, NH₃-TPD, XRD, SEM-EDS, Raman spectra, FT-IR, and TEM. Our catalytic results revealed synergistic role of acid and metal sites upon catalyst performance, whereupon high yields of hydrocarbons (86.9–100 wt.%) were obtained with selective cleavage of the methoxy and hydroxy groups under milder conditions. A kinetic study further identified the reaction mechanism and determined a rate law and partial reaction orders. This research advances the understanding of catalyst design for upgrading of the lignin or lignin monomers into value added chemicals. and on the other hand, contributes to sustainable development by maximizing biomass usage and providing environmentally friendly alternatives in renewable energy.