MnO 2 -Based Nanostructures as Catalysts for Electrochemical Oxygen Reduction in Alkaline Media

This paper reports a systematical study on the electrochemical properties of MnO2-based nanostructures as low-cost catalysts for oxygen reduction reaction (ORR) in alkaline media. The results show that the catalytic activities of MnO2 depend strongly on the crystallographic structures, following an order of α- > β- > γ-MnO2. Meanwhile, morphology is another important influential factor to the electrochemical properties. Among various micro and nanostructures, α-MnO2 nanospheres and nanowires outperform the counterpart microparticles. Furthermore, a new nanocomposite catalyst by depositing Ni nanoparticles on α-MnO2 nanowires (denoted as MnO2-NWs@Ni-NPs) was prepared and characterized. The as-prepared…