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Strontium iron molybdenum oxide as electrocatalyst for nitrous oxide reduction in solid oxide fuel cells.

Authors :
Holz, Laura I.V.
Loureiro, Francisco J.A.
Graça, Vanessa C.D.
Mikhalev, Sergey M.
Fernandes, Celina
Mendes, Adélio
Fagg, Duncan P.
Source :
International Journal of Hydrogen Energy. Feb2024, Vol. 54, p25-36. 12p.
Publication Year :
2024

Abstract

Nitrous oxide (N 2 O) is an environmentally damaging gas and alternative methods for its abatement are needed. In this work, we developed an electrochemical route using the mixed ionic electronic conductor Sr 2 Fe 1·5 Mo 0·5 O 6- δ (SFMO) as electrocatalyst for N 2 O reduction in the temperature range of 600–800 °C, at ambient pressure, for application in Solid Oxide Fuel Cells (SOFCs). The electrode mechanism, studied by electrochemical impedance spectroscopy (EIS), is discussed to involve a competition between both O 2 and N 2 O species, particularly at lower temperatures, where N 2 O thermal decomposition is lower. In terms of electrocatalytic properties, galvanostatic transients were used to assess N 2 O electroreduction on the SFMO electrode. The results showed that, after cathodic polarization, the N 2 O conversion increases. In particular, a highest Faradaic efficiency (| Λ|) of 3.94 was obtained at 600 °C. The reversibility of the mechanism was also assessed, and the results showed that the reaction rate returns to its open circuit value upon current interruption. This work indicates, therefore, that the electrochemical promotion of N 2 O reduction can be an attractive tool to be implemented for the reduction of this environmentally damaging gas in SOFC systems. • The viability of SFMO as electrocatalysts for N 2 O reduction is demonstrated. • The N 2 O electroreduction mechanism on the SFMO cathode is outlined. • Competition between O 2 electroreduction and N 2 O decomposition is suggested. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
03603199
Volume :
54
Database :
Academic Search Index
Journal :
International Journal of Hydrogen Energy
Publication Type :
Academic Journal
Accession number :
175411362
Full Text :
https://doi.org/10.1016/j.ijhydene.2023.05.251