Carbon-supported LaMnO3 was prepared by a reverse micelle method. Aqueous solutions of nitrates of La and Mn (A) and N(CH3)4OH (B) were brought into reverse micelle solutions by using NP-5 surfactant and cyclohexane solvent, respectively. Carbon powder was mixed with solution A and B stepwise, and the resulting suspension was subjected to a series of treatments to collect carbon powder loaded with a precursor of the oxide, which was calcined at 600°C under N2 flow to convert the precursor to LaMnO3. The gas diffusion-type oxygen electrode using the carbon-supported oxide thus prepared showed surprisingly high electrocatalytic activity for oxygen reduction. The current density was as high as 300 mA cm-2 at -80 mV vs. Hg/HgO in 8 M KOH at 60°C under air flow. This performance was maintained undisturbed for the 140 h testing period.
All Science Journal Classification (ASJC) codes
- General Chemical Engineering
- General Materials Science
- Physical and Theoretical Chemistry
- Electrical and Electronic Engineering