Shewanella‐mediated Biosynthesis of Manganese Oxide Micro‐/Nanocubes as Efficient Electrocatalysts for the Oxygen Reduction Reaction. Issue 1 (25th November 2014)

• Record Type: Journal Article
• Authors: Jiang, Congcong; Guo, Zhaoyan; Zhu, Ying; Liu, Huan; Wan, Meixiang; Jiang, Lei
• Is Part Of: ChemSusChem. Volume 8:Issue 1(2015:Jan.)
• Page Start: 158
• Page End: 163
• Publication Date: 2014-11-25
• Subjects: Green chemistry -- Periodicals; Sustainable engineering -- Periodicals; Chemistry -- Periodicals; Chemical engineering -- Periodicals; 660
• DOI: 10.1002/cssc.201402759
• Languages: English
• ISSNs: 1864-5631

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Developing efficient electrocatalysts for the oxygen reduction reaction (ORR) is critical for promoting the widespread application of fuel cells and metal–air batteries. Here, we develop a biological low‐cost, ecofriendly method for the synthesis of Mn<sub>2</sub>O<sub>3</sub> micro‐/nanocubes by calcination of MnCO<sub>3</sub> precursors in an oxygen atmosphere. Microcubic MnCO<sub>3</sub> precursors with an edge length of 2.5 μm were fabricated by dissimilatory metal‐reducing <italic>Shewanella loihica</italic> PV‐4 in the presence of MnO<sub>4</sub><sup>−</sup> as the sole electron acceptor under anaerobic conditions. After calcining the MnCO<sub>3</sub> precursors at 500 and 700 °C, porous Mn<sub>2</sub>O<sub>3</sub>‐500 and Mn<sub>2</sub>O<sub>3</sub>‐700 also showed microcubic morphology, while their edge lengths decreased to 1.8 μm due to thermal decomposition. Moreover, the surfaces of the Mn<sub>2</sub>O<sub>3</sub> microcubes were covered by granular nanoparticles with average diameters in the range of 18–202 nm, depending on the calcination temperatures. Electrochemical measurements demonstrated that the porous Mn<sub>2</sub>O<sub>3</sub>‐500 micro‐/nanocubes exhibit promising catalytic activity towards the ORR in an alkaline medium, which should be due to a synergistic effect of the overlapping molecular orbitals of oxygen/manganese and the hierarchically porous structures that are favorable for oxygen absorption. Moreover, these Mn<sub>2</sub>O<sub>3</sub> micro‐/nanocubes possess better stability than commercial Pt/C catalysts and methanol‐tolerance property in alkaline solution. Thus the <italic>Shewanella</italic>‐mediated biosynthesis method we provided here might be a new strategy for the preparation of various transition metal oxides as high‐performance ORR electrocatalysts at low cost.</p> </abstract>