TY - JOUR

T1 - Structural characterisation of the silica and alumina Zener pinning phases in nanocrystalline CeO2 by 29Si and 27Al nuclear magnetic resonance

AU - O'Dell, Luke A.

AU - Savin, Shelley L. P.

AU - Chadwick, Alan V.

AU - Smith, Mark E.

PY - 2008/12

Y1 - 2008/12

N2 - Nanocrystalline CeO2 samples have been manufactured using sol-gel techniques, containing either 15 % silica or 10 % alumina by weight to restrict growth of the ceria nanocrystals during annealing by Zener pinning. 29Si and 27Al MAS NMR have been used to investigate the structure of these pinning phases over a range of annealing temperatures up to 1000 °C, and their effect on the CeO2 morphology has been studied using electron microscopy. The silica pinning phase resulted in CeO2 nanocrystals of average diameter 19 nm after annealing at 1000 °C, whereas the alumina pinned nanocrystals grew to 88 nm at the same temperature. The silica pinning phase was found to contain a significant amount of inherent disorder indicated by the presence of lower n Qn species even after annealing at 1000 °C. The alumina phase was less successful at restricting the growth of the ceria nanocrystals, and tended to separate into larger agglomerations of amorphous alumina, which crystallised to a transition alumina phase at higher temperatures.

AB - Nanocrystalline CeO2 samples have been manufactured using sol-gel techniques, containing either 15 % silica or 10 % alumina by weight to restrict growth of the ceria nanocrystals during annealing by Zener pinning. 29Si and 27Al MAS NMR have been used to investigate the structure of these pinning phases over a range of annealing temperatures up to 1000 °C, and their effect on the CeO2 morphology has been studied using electron microscopy. The silica pinning phase resulted in CeO2 nanocrystals of average diameter 19 nm after annealing at 1000 °C, whereas the alumina pinned nanocrystals grew to 88 nm at the same temperature. The silica pinning phase was found to contain a significant amount of inherent disorder indicated by the presence of lower n Qn species even after annealing at 1000 °C. The alumina phase was less successful at restricting the growth of the ceria nanocrystals, and tended to separate into larger agglomerations of amorphous alumina, which crystallised to a transition alumina phase at higher temperatures.

KW - Nanocrystal

KW - Nanocrystalline

KW - Ceria

KW - CeO2

KW - Zener pinning

KW - Nuclear magnetic resonance

KW - Restricting growth

KW - Sol-gel

KW - 29Si NMR

KW - 27Al NMR

KW - Silica

KW - Alumina

KW - Instrumentation

U2 - 10.1007/s11051-007-9354-z

DO - 10.1007/s11051-007-9354-z

M3 - Journal article

VL - 10

SP - 1263

EP - 1270

JO - Journal of Nanoparticle Research

JF - Journal of Nanoparticle Research

SN - 1388-0764

IS - 8

ER -