title: Manganese dioxide as an alternative cathodic catalyst to platinum in microbial fuel cells.
abstract: In this paper, three manganese dioxide materials, alpha-MnO(2), beta-MnO(2), gamma-MnO(2) were tested as alternative cathodic catalysts to platinum (Pt) in air-cathode microbial fuel cells (MFCs). Prepared via hydrothermal method, the manganese dioxides were characterized by X-ray powder diffraction patterns (XRD), the Brunauer-Emmett-Teller (BET) method and their average oxidation states (AOS) were determined by the potential voltammetric titration method. The electro-catalytic activity of MnO(2) in neutral pH solution was determined by linear sweep voltammetry (LSV) and the results showed that all manganese dioxides can catalyze oxygen reduction reaction (ORR) in neutral medium with different catalytic activities. beta-MnO(2) appeared to hold the highest catalytic activity due to its highest BET surface area and AOS. Beta-MnO(2) was further used as cathode catalyst in both cube and tube air-cathode MFCs, in which using Klebsiella pneumoniae (K. pneumoniae) biofilm as biocatalyst and utilizing glucose as a substrate in the anode chamber. It was found that tube MFC produced higher output power, with the maximum volumetric power density of 3773+/-347 mW/m(3), than cube MFC. This study suggests that using beta-MnO(2) instead of Pt could potentially improve the feasibility of scaling up MFC designs for real applications by lowering production cost.
authors.affiliation: Department of Chemistry and Environment, South China Normal University, Guangzhou 510006, China.
authors.forename: Lixia
authors.initials: L
authors.lastname: Zhang
authors.forename: Chengshuai
authors.initials: C
authors.lastname: Liu
authors.forename: Li
authors.initials: L
authors.lastname: Zhuang
authors.forename: Weishan
authors.initials: W
authors.lastname: Li
authors.forename: Shungui
authors.initials: S
authors.lastname: Zhou
authors.forename: Jintao
authors.initials: J
authors.lastname: Zhang
mesh_terms: D001674:Bioelectric Energy Sources / Q000382:microbiology*; D002384:Catalysis; D004563:Electrochemistry; D004566:Electrodes; D005947:Glucose / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007711:Klebsiella pneumoniae / Q000378:metabolism*; D017895:Manganese Compounds / Q000737:chemistry*; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D017895:Manganese Compounds; D010087:Oxides; D010984:Platinum; D005947:Glucose; D010100:Oxygen; C016552:manganese dioxide