Ce-doped LaNiO₃ perovskites: Insights into oxygen mobility and adsorption for catalytic deoxygenation processes

Efficient and thermally stable catalysts are crucial for enhancing bio-oils through deoxygenation reactions, a key step toward sustainable fuel production. In this study, we used a hybrid approach combining density functional theory (DFT) and molecular dynamics (MD) simulations to explore the effects of Ce doping on the structural, electronic, and oxygen diffusion properties of LaNiO₃-based perovskites (La₁₋ₓCeₓNiO₃). DFT simulations showed that Ce substitution at the La site improved the structural stability of the perovskite framework, evident from the decrease in total energy and changes in the electronic state near the Fermi level. MD simulations assessed oxygen ion mobility and oxygen adsorption energy across various Ce doping concentrations (x = 0 to 1). The results revealed that oxygen diffusion peaked at x = 0.58, with maximum mobility at this concentration, suggesting its suitability for applications requiring efficient oxygen transport, such as catalytic deoxygenation. Adsorption energy calculations further showed that at x = 0.58, the surface exhibited enhanced stability and favorable oxygen adsorption energy, indicating its potential for catalytic processes with balanced oxygen-surface interactions. By evaluating thermodynamic stability, oxygen-vacancy formation energy, oxygen mobility, and adsorption energy, we identified an optimal Ce doping range of x ≈ 0.5 – 0.6. These findings demonstrate the potential of Ce-doped LaNiO₃ perovskites as promising catalysts for the deoxygenation of oxygen-rich organic compounds, advancing cleaner, renewable fuel technologies.