A more quantitatively controllable triple phase boundary (TPB) of a lanthanum strontium manganite/yttria-stabilized zirconia (LSM/YSZ) interface was constructed by using an YSZ ionic probe with well-defined dimensions. A bar-shaped, dense YSZ sintered body was employed as an ionic probe and embedded in the pellet-shaped, dense LSM bulk. The TPB length of the LSM/YSZ interface can be simply determined from the circumference of the YSZ bars. To identify the reaction mechanism of the oxygen reduction reaction (ORR) at the TPB of the LSM/YSZ interface, limited-contact AC impedance spectroscopy was used; this distinguished the LSM/YSZ interface related polarization from other polarizations present in the Pt/LSM/YSZ/Pt electrochemical cell. By analyzing the electrode-related polarizations in the electrochemical cell with the geometrically quantified YSZ ionic probe, the rate determining step of the ORR was the diffusion of adsorbed oxygen along the LSM bulk surface. In this paper, emphasis is placed on the experimental versatility and the limitations of our designed electrochemical analysis with bar-shaped ionic probes.
Bibliographical noteFunding Information:
This work was supported by the New & Renewable Energy Core Technology Program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP), a granted financial resource from the Ministry of Trade, Industry & Energy, Republic of Korea (No. 20143030031430 ), and partially funded by the institutional research program of KIST.
All Science Journal Classification (ASJC) codes
- Renewable Energy, Sustainability and the Environment
- Energy Engineering and Power Technology
- Physical and Theoretical Chemistry
- Electrical and Electronic Engineering