Targeted design of α-MnO2 based catalysts for oxygen reduction

0455794 - ÚFCH JH 2017 RIV GB eng J - Článek v odborném periodiku
Lehtimäki, Matti - Hoffmannová, Hana - Boytsová, O. - Bastl, Zdeněk - Bush, M. - Halck, N. B. - Rossmeisl, J. - Krtil, Petr
Targeted design of α-MnO2 based catalysts for oxygen reduction.
Electrochimica acta. Roč. 191, FEB 2016 (2016), s. 452-461. ISSN 0013-4686. E-ISSN 1873-3859
GRANT EU: European Commission(XE) 214936 - ELCAT
Institucionální podpora: RVO:61388955
Klíčová slova: electrocatalysis * oxygen reduction * MnO2
Kód oboru RIV: CG - Elektrochemie
Impakt faktor: 4.798, rok: 2016

The paper focuses on theoretical and experimental aspects of an oxide surface optimization for oxygen reduction reaction (ORR). Various doped α-MnO2 based electrocatalysts were prepared by microwave-assisted hydrothermal synthesis and electrochemically characterized to validate density functional theory (DFT) based predictions of the oxidation state and local structure effects on the catalytic activity of α-MnO2 catalysts in ORR. Both theory and experiments conclude that the highest activity in ORR is to be expected in the case of clustered Mn3+ sites which yield activity comparable with that of the polycrystalline Pt. These active sites have to be formed under in-operando conditions and their formation is hindered in doped α-MnO2 catalysts. The activity of the other conceivable active sites based on non-clustered Mn3+ or Mn4+ is inferior to that of clustered Mn3+. The activation of Mn3+ or Mn4+ based active sites leads to a shift in selectivity of the ORR process towards 2 electron formation of hydrogen peroxide.


Trvalý link: http://hdl.handle.net/11104/0256430