Thermodynamic stability of niobium-doped ceria surfaces

• Published in: Journal of molecular structure Vol. 1265; p. 133416
• Main Authors: Razmgar, Kourosh, Altarawneh, Mohammednoor, Oluwoye, Ibukun, Altarawneh, Nuseiba, Senanayake, Gamini
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 05.10.2022
• Subjects: Ceria; Cerium (IV) Oxide; DFT; Niobium; Stability; DFT; Stability; Cerium (IV) Oxide; Niobium; Ceria
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/j.molstruc.2022.133416

•This study investigates structures and thermodynamic stability of Nb-CeO2 configurations.•Most stable Ce-Nb-O configuration is obtained when Nb atoms supersede top-layer o atoms.•Calculated lattice constants reflects very well our measured value.•EDS measurements provided relative atomic distributions.•Results herein could be useful in fine-tuning catalytic attributes of ceria-based materials. Ceria (CeO2) displays a profound catalytic capacity even when utilized as a stand-alone material. Catalyzed reactions by ceria could be enhanced when it is decorated with a trace content of d or f-metals. This study addresses the stability and properties of niobium incorporated ceria surfaces. Doping a trace amount of metals often alter catalytic properties of the host metal oxide. Herein, we investigate mixed Ce-Nb-O oxides with a prime focus on the surface free energy, lattice constant, as well as atomic charges and density of states. It was found that the most stable Ce-Nb-O configuration is obtained when Nb atoms supersede top-layer O atoms at highest niobium occupancy where the surface energy decreases by 0.3 eV/Å2 compared to neat ceria surface. It was also shown that the changes in lattice constants in this configuration is in accord with data obtained from X-Ray Diffraction patterns. Results from this study could be useful in fine-tuning catalytic attributes of ceria-based materials.