121st General Meeting of the KCS

Type Poster Presentation
Area Material Chemistry
Room No. Event Hall
Time 4월 20일 (금요일) 11:00~12:30
Code MAT.P-370
Subject Synthesis of Uniform Manganese Cobalt Oxide Nanoparticles for Oxygen Reduction Electrocatalysis
Authors SUNGLUN KWON, JUNYEONG KIM, Ho Jung Hwang, Jong Hyeon Lee*
Department of Chemistry, The Catholic University of Korea, Korea
Abstract Oxygen reduction reaction (ORR) is a crucial process to transfer and store the energy in fuel cell and metal-air batteries. Platinum nanoparticles supported on porous carbon show a relatively high electrocatalytic performance. However, the high cost and restricted resources of Pt are major challenges for commercialization. Recently, transition metal spinel oxide such as Co3O4 exhibits promising ORR activity that could be enhanced by doping with Mn, Fe, Ni etc. due to a good electrical conductivity. Crystallinity and anti-aggregation of spinel oxide nanoparticles are also essential in high ORR activity. In this study, we have synthesized MnxCo3-xO4 (x=1~0) nanocubes by a topochemical reaction of exfoliated Co(OH)2 nanosheet, which shows unique nanoscopic properties: a larger surface area of active hydroxides and a much narrower oxidation–reduction potential for the Co2+ ions in the hydroxide layer than those of the bulk α-Co(OH)2. Our reaction does not require an additional high-temperature calcination for crystalline spinel phase and an organic stabilizer for anti-aggregation. We found that the size of MnxCo3-xO4 nanocube are controlled by concentration of Mn ions from 150 nm to 15 nm. We have measured the ORR activities by using cyclic voltammetry and linear sweep voltammetry under O2 saturated 0.1 M KOH solutions. The incorporation of Mn in cobalt oxide nanoparticles has dramatically reduced the onset potential and increased the current density. When the value of x reaches 0.005, the spinel oxide nanoparticle showed a best performance in ORR.
E-mail kwonsh5@hanmail.net