Effects of Sr/Ti-ratio in SrTiO3-based SOFC anodes investigated by the use of cone-shaped electrodes

• In this work the A-site deficiency limit for undoped SrTiO3, calcined in air or reducing atmosphere, was investigated. XRD and SEM analyses showed that when using the solid-state synthesis route it was difficult to achieve any A-site deficiency. Even very small deviations from unity in the Sr/Ti-ratio resulted in impurity phases. The effects of Sr/Ti-ratio on the performance of SrTiO3 anodes for solid oxide fuel cells (SOFCs) was investigated by impedance spectroscopy with cone-shaped electrodes. The electrocatalytic activity of the SrTiO3 cone samples, with various amount of reduced titanium dioxide phases (Magnéli phases), was investigated for oxidation of H2 at 700 °C. High temperature treatment at 1000 °C, between the measurements at 700 °C, showed that high content of Magnéli phases leads to faster degradation of the activity. The suitability for using cone-shaped electrodes as a tool for investigating electrode materials is discussed.

Ämnesord

NATURVETENSKAP  -- Kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences (hsv//eng)

Nyckelord

Magnéli phases

Area normalization

A-site deficiency

Cone-shaped electrode

SrTiO3

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