Principal Investigator Yang Shao-Horn
We study epitaxial thin film perovskite electrodes grown with pulsed laser deposition (PLD). Well-defined electrochemical measurements (e.g. electrochemical impedance spectroscopy (EIS)) are carried out on microelectrodes prepared with photolithography.
Interestingly, (001) orientated La0.8Sr0.2CoO(3-δ) (LSC113) epitaxial thin films exhibit higher ORR activity than bulk (1–2 orders of magnitude in the oxygen surface exchange coefficient, kq). The activity can be further enhanced with the decoration of (La0.5Sr0.5)2CoO(4±δ) (LSC214) particles on the surface (overall up to 3–4 orders of magnitude in kq over bulk), where the heterostructured interface between surface LSC113 and LSC214 may contribute to the enhanced ORR activity. In addition, the catalytic activity strongly depends on the amount and kind of secondary surface phases, e.g. the catalytic activity of LSC113 surfaces can be modified by decoration with particles composed of Lanthanum-(La) , Strontium-(Sr), and Cobalt-(Co)based (hydr)oxides show different kq values.