Proton Conductivity in Mixed B-Site Doped Perovskite Oxide BaZr[sub 0.5]In[sub 0.25]Yb[sub 0.25]O[sub 3 - delta]
Journal article, 2010

A wet chemical route was used to prepare the oxygen deficient codoped perovskite oxide BaZr0.5In0.25Yb0.25O3−. Analysis of X-ray powder diffraction data showed that the sample belongs to the cubic crystal system with space group Pmm. Dynamic thermogravimetric (TG) analysis confirmed complete filling of oxygen vacancies (V) by protonic defects (OH) during the hydration process. The proton conductivity was investigated by impedance spectroscopy. The bulk and total conductivities of prehydrated BaZr0.5In0.25Yb0.25O3− were found to be 8.5×10−4 and 2.2×10−5 S cm−1, respectively, at 300°C. The total conductivity in the codoped perovskite oxide was higher compared to that of the respective single doped perovskite oxides with the same doping level. The bulk and grain-boundary mobility and diffusion coefficients of protons were calculated at 200°C using impedance and TG data to obtain the conductivity and proton concentration, respectively. The high bulk diffusivity (2.3×10−7 cm2 s−1) was obtained which indicates that the protons are more free to move in the heavily doped matrix compared to the lightly doped systems where trapping of protons occurs.

barium compounds

X-ray diffraction

zirconium compounds

proton exchange membrane fuel cells

vacancies (crystal)

thermal analysis

Author

Istaq Ahmed

Chalmers, Chemical and Biological Engineering, Environmental Inorganic Chemistry

FRANCIS GACHAO KINYANJUI

Chalmers, Chemical and Biological Engineering, Environmental Inorganic Chemistry

Seikh Mohammad Habibur Rahman

Chalmers, Chemical and Biological Engineering, Environmental Inorganic Chemistry

Patrick Steegstra

University of Gothenburg

Sten Eriksson

Chalmers, Chemical and Biological Engineering, Environmental Inorganic Chemistry

Elisabet Ahlberg

University of Gothenburg

Journal of the Electrochemical Society

0013-4651 (ISSN)

Vol. 157 12 B1819-B1824

Subject Categories

Other Materials Engineering

Chemical Sciences

DOI

10.1149/1.3494119

More information

Created

10/7/2017