JSSE 12 (2008) 1541-1548 pre-print.pdf (701.82 kB)
Underpotential surface reduction of mesoporous CeO2 nanoparticle films
journal contribution
posted on 2013-01-11, 11:41 authored by Charles Y. Cummings, Susan J. Stott, Michael J. Bonne, Karen J. Edler, Pauline M. King, Roger J. Mortimer, Frank MarkenThe formation of variable-thickness CeO2 nanoparticle mesoporous films from a colloidal nanoparticle solution (approximately 1–3-nm-diameter CeO2) is demonstrated using a layer-by-layer deposition process with small organic binder molecules such as cyclohexanehexacarboxylate and phytate. Film growth is characterised by scanning and transmission electron microscopies, X-ray scattering and quartz crystal microbalance techniques. The surface electrochemistry of CeO2 films before and after calcination at 500 °C in air is investigated. A well-defined Ce(IV/III) redox process confined to the oxide surface is observed. Beyond a threshold potential, a new phosphate phase, presumably CePO4, is formed during electrochemical reduction of CeO2 in aqueous phosphate buffer solution. The voltammetric signal is sensitive to (1) thermal pre-treatment, (2) film thickness, (3) phosphate concentration and (4) pH. The reversible ‘underpotential reduction’ of CeO2 is demonstrated at potentials positive of the threshold. A transition occurs from the reversible ‘underpotential region’ in which no phosphate phase is formed to the irreversible ‘overpotential region’ in which the formation of the cerium(III) phosphate phase is observed. The experimental results are rationalised based on surface reactivity and nucleation effects.
History
School
- Science
Department
- Chemistry
Citation
CUMMINGS, C.Y., 2008. Underpotential surface reduction of mesoporous CeO2 nanoparticle films. Journal of Solid State Electrochemistry, 12 (12), pp. 1541 - 1548.Publisher
© SpringerVersion
- AM (Accepted Manuscript)
Publication date
2008Notes
This article was published in the Journal of Solid State Electrochemistry, [© Springer] and the original publication is available at www.springerlink.comISSN
1432-8488Publisher version
Language
- en