Abstract

Understanding and controlling the performance of ceria nanoparticle (CNP) catalysts requires knowledge of the detailed structure and property of CNP surfaces and any attached functional groups. Here we report thermogravimetric analysis results showing that hydrothermally synthesized ∼30 nm CNPs are decorated with 12.9 hydroxyl groups per nm2 of CNP surface.Quantum mechanical calculations of the density and distribution of bound surface groups imply a scaling relationship for surface group density that balances formal charges in the functionalized CNP system. Computational results for CNPs with only hydroxyl surface groups yield a predicted density of bound hydroxyl groups for ∼30 nm CNPs that is ∼33% higher than measured densities. Quantitative agreement between predicted and measured hydroxylsurface densities is achieved when calculations consider CNPs with both –OH and –Ox surface groups. For this more general treatment of CNP surface functionalizations, quantum mechanical calculations predict a range of stable surface group configurations that depend on the chemical potentials of O and H, and demonstrate the potential to tune CNP surfacefunctionalizations by varying temperature and/or partial pressures of O2 and H2O.

Document Type

Article

Publication Date

2-21-2014

Notes/Citation Information

Published in Journal of Chemical Physics, v. 140, no. 7, 074703.

Copyright 2014 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.

This article appeared in J. Chem. Phys. 140, 074703 (2014) and may be found at http://dx.doi.org/10.1063/1.4864378.

Digital Object Identifier (DOI)

http://dx.doi.org/10.1063/1.4864378

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