Thermal stability and performance enhancement of nano-porous platinum cathode in solid oxide fuel cells by nanoscale ZrO2 capping

•Nanoscale ZrO2 were deposited on nano-porous Pt by atomic layer deposition (ALD).•10 ALD-cycles of ZrO2 (~ 1.6 nm) effectively confined the thermally-driven agglomeration of Pt cathode.•The ZrO2 capping has also unexpectedly lowered the polarization resistance of Pt cathode.

This work demonstrates a nanoscale zirconia layer coated by atomic layer deposition (ALD) with only a few coating cycles on a nano-porous platinum cathode surface to serve as a physical confinement to prevent the electrode agglomeration under high temperature operation, and at the same time to enhance the cathode oxygen reduction activity. The resulted enhancement in cathode electrochemical performance can arise from the discontinuous ZrO2 film that facilitates the oxygen adsorption on cathode surface and decreases the oxygen adsorption–desorption resistance.