Hydrodeoxygenation of lignin model compounds under mild condition over Pd/Nb2O5 Catalyst

Biorefineries offer a renewable alternative to petroleum refining, and lignin valorization is key to advancing beyond fuel/energy applications toward higher-value chemicals. Hydrodeoxygenation (HDO) of lignin-derived phenolics is a critical step for converting these compounds into value-added aromatic hydrocarbons. This work investigated the HDO reactivity of guaiacol (2-methoxyphenol), a model lignin monomer, over a palladium catalyst supported on niobium pentoxide (Pd/Nb₂O₅), synthesized hydrothermally with urea to study Pd distribution. Reactions were performed in a 50 mL batch reactor under mild conditions (200 °C, 15 bar H₂). The catalyst was characterized by XRD, TGA, TEM, N2 physisorption, Temperature-Programmed Reduction, and DRIFTS under CO to probe metal-support interactions and active-site nature. Products were analyzed by GC-MS and HPLC-UV (C18 column). Preliminary results show good Pd/Nb₂O₅ performance in guaiacol HDO, demonstrating that Pd metallic sites combined with niobia's oxophilicity govern activity and selectivity.