Nanometer Yttria-doped Ceria Shell by Atomic Layer Deposition over Porous Pt for Improved Oxygen Reduction Reactions

Designing highly active and thermally stable electrodes is crucial for realizing low-temperature solid oxide fuel cells (LT-SOFCs) with excellent performance. In this study, we fabricated an yttria-doped ceria (YDC) shell layer by atomic layer deposition (ALD) over a Pt cathode by controlling the doping concentration of yttria in YDC film. The exchange current density was enhanced by a factor of five when the ALD YDC shell layer was deposited onto the cathode surface compared to the bare Pt cathode, resulting in an 80% decrease in the activation resistance of the 19 mol%-doped ALD YDC-overcoated Pt cathode compared to that of the bare Pt cathode. Furthermore, the thermal stability was enhanced in low-to-medium-doped (7-19 mol%) ALD YDC-coated Pt cathodes, whereas the highly doped (31 mol%) cathode showed a relatively marginal improvement in stability.