Metal-air batteries are one of the most promising electrochemical systems for energy storage and conversion. Herein we report promising results by exploiting manganese dioxide nanoparticles as ORR electrocatalysts. MnO2 nanorods were prepared through a hydrothermal synthesis, i.e. by varying both the salt precursors (Le. manganese sulphate or chloride) and the oxidizing agents (Le. ammonium persulfate or potassium permanganate). All the nanopowders were finely characterized on structural, morphological and surface points of view. Then, their electrocatalytic power was tested either in aqueous 0.1 M potassium hydroxide or in Tetra Ethylene Glycol Dimethyl Ether (TEGDME)/LiNO3 0.5 M electrolytes, by using Gas Diffusion Electrodes (GDEs) and Glassy Carbon (GC) as cathodes, respectively. All the nanoparticles promoted the ORR by causing a shift of the onset potential up to 100 mV in both solvents. Nevertheless, this shift was different according to the solvent/electrolyte used: in the case of the ether-based solvent, different values are obtained by adopting the synthesized MnO2 powders. Thus, we hypothesized that the structural/surface properties of MnO2 samples are leveled in the aqueous medium (Le. in a OH rich solvent, the hydroxyls can interact with the homologs on the MnO2 surface), contrary to what occurs in the organic solvent. Furthermore, a different behavior was observed also on the kinetic point of view thus leading to diverse interpretations of the oxygen reduction mechanism, especially in TEGDME.
Ad hoc tailored electrocatalytic MnO2nanorods for the oxygen reduction in aqueous and organic media / S. Orsini, E. Pargoletti, A. Vertova, A. Minguzzi, C. Locatelli, S. Rondinini, G. Cappelletti. - In: JOURNAL OF ELECTROANALYTICAL CHEMISTRY. - ISSN 1572-6657. - 808(2018 Jan), pp. 439-445.
|Titolo:||Ad hoc tailored electrocatalytic MnO2nanorods for the oxygen reduction in aqueous and organic media|
PARGOLETTI, ELEONORA (Corresponding)
|Parole Chiave:||Aqueous medium; Electrocatalyst; Manganese dioxide; Metal-air devices; Oxygen Reduction Reaction (ORR); Tetra Ethylene Glycol Dimethyl Ether (TEGDME); Analytical Chemistry; Chemical Engineering (all); Electrochemistry|
|Settore Scientifico Disciplinare:||Settore CHIM/02 - Chimica Fisica|
|Data di pubblicazione:||gen-2018|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1016/j.jelechem.2017.05.035|
|Appare nelle tipologie:||01 - Articolo su periodico|