• Hughes, Lucia
• Downing, Clive
• Yadav, Neelam
• Roy, Ahin
• Vij, Jagdish K.
• Browne, Michelle P.
• Nicolosi, Valeria

Abstract

<jats:title>Abstract</jats:title><jats:p>Microwave heating provides a rapid method for the heterogeneous nucleation of noble metal particles on perovskite support materials for electrocatalytic purposes. To succeed, dielectric tuning of perovskite materials becomes fundamental. Herein, the dielectric engineering of the BaMnO<jats:sub>3</jats:sub> perovskite system is carried out through the use of B‐site doping to give BaTi<jats:sub>0.5</jats:sub>Mn<jats:sub>0.5</jats:sub>O<jats:sub>3</jats:sub>. Using a combination of atomic‐scale imaging and electron energy loss spectroscopy (EELS), the preferential filling of the M1 and M3 B‐sites with Mn and Ti ions in the 12R‐rhombohedral perovskite structure is established. While the addition of Ti in the BaMnO<jats:sub>3</jats:sub> system has no detrimental effects on the presence of the oxygen reduction reaction (ORR) active Mn<jats:sup>3+</jats:sup> states at the surface, it does alter the dielectric constant and loss tangent, thus facilitating the heterogeneous nucleation of Pt nanoparticles on BaTi<jats:sub>0.5</jats:sub>Mn<jats:sub>0.5</jats:sub>O<jats:sub>3</jats:sub> via rapid microwave heating. Higher Pt loading regimes are found to increase the size and aggregation of the nucleated particles, thus reducing their ORR activity. Therefore, lower Pt loading not only reduces costs but improves overall activity. This work represents future possibilities for the dielectric engineering of perovskite and similar support materials to aid in the quick and easy formation of stable noble metal‐support catalytic systems.</jats:p>

Topics

• nanoparticle
• perovskite
• impedance spectroscopy
• surface
• Oxygen
• dielectric constant
• electron energy loss spectroscopy