Synergistic catalyst Ru/NbOPO 4 /TiO 2 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 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 this work, a series of multifunctional Ru/NbOPO4/TiO2 catalysts with varying surface acidic properties are developed and explored upon hydrogenolysis of lignin model compound eugenol. Textural and surface acid-base properties of the prepared materials are studied by N2-physisorption, NH3-TPD, XRD, SEM-EDS, Raman spectra, FT-IR, and TEM. Catalytic results reveal synergistic role of acid and metal sites upon catalyst performance, whereupon high yields of hydrocarbons (86.9–100 wt.%) are obtained with selective cleavage of the methoxy and hydroxy groups under milder conditions. Further study identifies the reaction mechanism and determines 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.