Role of Ni species on CeO2 catalysts for selective hydrodeoxygenation of bio-oil

High-performance Ni/CeO 2 catalyst achieves ∼ 100% m-cresol conversion. • The Ni doping reduces oxygen vacancy formation energy and modulates electronic structure. • The methylcyclohexane as the thermodynamically favored pathway. The conversion of waste biomass into biofuels via fast pyrolysis followed by hydrodeoxygenation (HDO) represents a promising route for sustainable energy production. This study examines the selective HDO of bio-oil, using m-cresol as a model compound, over a Ni/CeO 2 catalyst to enhance the yield and stability of hydrocarbon fuels. Experimental investigations coupled with density functional theory (DFT) calculations were employed to elucidate the reaction mechanism and identify active sites. Under optimized conditions (300 °C, 3 MPa H 2 ), the Ni/CeO 2 catalyst achieved nearly complete conversion of m-cresol, with methylcyclohexane as the dominant product. DFT results indicate that Ni doping lowers the oxygen vacancy formation energy and modifies the electronic structure of CeO 2 , thereby enhancing catalytic activity. A detailed reaction network was established, revealing that elevated H 2 pressures favor methylcyclohexane formation, whereas higher temperatures promote toluene and benzene production. This work underscores the efficacy of Ni/CeO 2 catalysts in bio-oil upgrading, contributing to the development of efficient renewable fuel processes. Download: Download high-res image (188KB) Download: Download full-size image