Proton conduction in nanocrystalline oxides

M. Shirpour, R. Merkle, G. Gregori

In the last years, a number of studies have reported unexpected proton conduction in nanocrystalline doped zirconia, ceria as well as titania at low temperatures (T < 200 °C). The purpose of our investigations has been aimed at identifying, whether the preferential proton transport occurs along the grain boundaries or rather at the adsorbed water/solid interface. The experimental results suggest proton conduction to occur at the water/oxide interface and not at the grain boundaries.

Arrhenius plots of the conductivity of (a) nanocrystalline undoped-CeO2 and (b) nanocrystalline Gd-doped CeO2 under dry and wet atmospheres (pO2 = 1 bar, pH2O = 20 mbar) Reproduced with permission of the PCCP Owner Societies. — Arrhenius plots of the conductivity of (a) nanocrystalline undoped-CeO₂ and (b) nanocrystalline Gd-doped CeO₂ under dry and wet atmospheres (pO₂ = 1 bar, pH₂O = 20 mbar) Reproduced with permission of the PCCP Owner Societies.

Arrhenius plots of the conductivity of (a) nanocrystalline undoped-CeO₂ and (b) nanocrystalline Gd-doped CeO₂ under dry and wet atmospheres (pO₂ = 1 bar, pH₂O = 20 mbar) Reproduced with permission of the PCCP Owner Societies.

Publications:

M. Shirpour, G. Gregori, R. Merkle, and J. Maier, “On the proton conductivity in pure and gadolinium doped nanocrystalline cerium oxide”, Phys. Chem. Chem. Phys., 13 [3], 937-940 (2011). DOI: 10.1039/c0cp01702g

G. Gregori, M. Shirpour, and J. Maier, “Proton conduction in dense and porous nanocrystalline ceria thin films”, Adv. Funct. Mater. (2013). DOI: 10.1002/adfm.201300527 – in press; available online.