Thickness Dependence of Oxygen Reduction Reaction Kinetics on Strontium-Substituted Lanthanum Manganese Perovskite Thin-Film Microelectrodes

• Main Authors: La O', Gerardo Jose Cordova (Contributor), Shao-Horn, Yang (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Mechanical Engineering (Contributor), Massachusetts Institute of Technology. Electrochemical Energy Laboratory (Contributor)
• Format: Article
• Language: English
• Published: Electrochemical Society, 2013-06-13T19:51:24Z.
• Subjects: Article
• Online Access: Get fulltext

Oxygen reduction reaction (ORR) kinetics was investigated on dense La₀.₈Sr₀.₂MnO₃ microelectrodes as a function of temperature and microelectrode thickness using electrochemical impedance spectroscopy. The surface oxygen exchange and mixed bulk/three-phase-boundary (TPB) charge transfer process were found to control ORR kinetics at high and low temperatures, respectively. The transition temperature from the mixed bulk/TPB charge transfer control to surface oxygen exchange was found to be highly dependent on the microelectrode thickness (~600degrees C for 65 nm vs ~800degreesC for 705 nm). These findings can be used to guide the design of electrodes that can operate at intermediate temperatures.
National Science Foundation (U.S.) (Materials Research Science and Engineering Center (MRSEC) Program, Award DMR-0819762)
National Science Foundation (U.S.) (NSF grant no. CBET-0844526)