Multiscale Modeling of Agglomerated Ceria Nanoparticles: Interface Stability and Oxygen Vacancy Formation

• Published in: Frontiers in chemistry 2019-05, Vol.7, p.203-203
• Main Authors: Kim, Byung-Hyun, Kullgren, Jolla, Wolf, Matthew J, Hermansson, Kersti, Broqvist, Peter
• Format: Article
• Language: English
• Subjects: agglomeration; cerium dioxide; Chemistry; density functional theory; multiscale modeling; nanoparticles; reducible oxides; self-consistent charge density functional tight binding
• ISSN: 2296-2646; 2296-2646
• DOI: 10.3389/fchem.2019.00203

The interface formation and its effect on redox processes in agglomerated ceria nanoparticles (NPs) have been investigated using a multiscale simulation approach with standard density functional theory (DFT), the self-consistent-charge density functional tight binding (SCC-DFTB) method, and a DFT-parameterized reactive force-field (ReaxFF). In particular, we have modeled Ce O NP pairs, using SCC-DFTB and DFT, and longer chains and networks formed by Ce O or Ce O NPs, using ReaxFF molecular dynamics simulations. We find that the most stable {111}/{111} interface structure is coherent whereas the stable {100}/{100} structures can be either coherent or incoherent. The formation of {111}/{111} interfaces is found to have only a very small effect on the oxygen vacancy formation energy, . The opposite holds true for {100}/{100} interfaces, which exhibit significantly lower values than the bare surfaces, despite the fact that the interface formation eliminates reactive {100} facets. Our results pave the way for an increased understanding of ceria NP agglomeration.