• Brearley, Adrian
• Garzon, Fernando H.
• Benavidez, Angelica

Abstract

<jats:p>Doped perovskite metal oxide catalysts of the form A(B<jats:sub>x</jats:sub>M<jats:sub>1-x</jats:sub>)O<jats:sub>3-δ</jats:sub> have been instrumental in the development of solid oxide electrolyzers/fuel cells. In addition, this material class has also been demonstrated to be effective as a heterogeneous catalyst. Co-doped barium niobate perovskites have shown remarkable stability in highly acidic CO<jats:sub>2</jats:sub> sensing measurements/environments (1). However, the reason for their chemical stability is not well understood.Doping with transition metal cations for B site cations often leads to exsolution under reducing conditions. Many perovskites used for the oxidative coupling of methane (OCM) or the electrochemical oxidative coupling of methane (E-OCM) either lack long term stability, or catalytic activity within these highly reducing methane environments. The Mg and Fe co-doped barium niobate BaMg<jats:sub>0.33</jats:sub>Nb<jats:sub>0.67-x</jats:sub>Fe<jats:sub>x</jats:sub>O<jats:sub>3-δ</jats:sub> shown activity in E-OCM reactors over long periods (2) (&gt;100 hrs) with no iron metal exsolution observed by diffraction or STEM EDX measurements. In contrast, iron decorated BaMg<jats:sub>0.33</jats:sub>Nb<jats:sub>0.67</jats:sub>O<jats:sub>3 </jats:sub>showed little C2 conversion activity.</jats:p>

Topics

• perovskite
• impedance spectroscopy
• chemical stability
• iron
• Energy-dispersive X-ray spectroscopy
• Barium