title: Catalytic characteristics of MnO2 nanostructures for the O2 reduction process.
abstract: Nanorods with an α type MnO(2) structure and a diameter ranging from 25 to 40 nm, along with tipped needles with a β MnO(2) structure and a diameter of 100 nm were obtained. The 25 nm diameter α MnO(2) nanorods showed the best catalytic activity for dissociation of HO(2)(-) formed during oxygen reduction in a KOH solution. The MnO(2) nanostructures preferably followed a two-electron oxygen reduction mechanism in a LiOH solution. The size of the catalyst also affected the specific capacities of the non-aqueous Li/O(2) batteries fabricated using the MnO(2) based air electrode. The highest specific capacity of 1917 mA h g(-1) was obtained for an α MnO(2) nanorod catalyst having a diameter of 25 nm. The cation present in the MnO(2) nanostructures appears to determine the catalytic activity of MnO(2).
authors: Department of Materials Science and Engineering, Chonnam National University, Bukgu, Gwangju, Korea.
authors: Ramchandra S
authors: RS
authors: Kalubarme
authors: Min-Seung
authors: MS
authors: Cho
authors: Kwi-Sub
authors: KS
authors: Yun
authors: Tae-Sin
authors: TS
authors: Kim
authors: Chan-Jin
authors: CJ
authors: Park
mesh_terms: D002384:Catalysis; D017895:Manganese Compounds / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry*
chemical_list: D017895:Manganese Compounds; D010087:Oxides; D010100:Oxygen; C016552:manganese dioxide