Spray‐Flame‐Prepared LaCo<sub>1–<i>x</i></sub>Fe<sub>x</sub>O<sub>3</sub> Perovskite Nanoparticles as Active OER Catalysts: Influence of Fe Content and Low‐Temperature Heating
Barış Alkan, Danea Medina, Joachim Landers, Markus Heidelmann, Ulrich Hagemann, Soma Salamon, Corina Andronescu, Heiko Wende, Christof Schulz, Wolfgang Schuhmann, Hartmut Wiggers
Abstract
Abstract Spray‐flame synthesis was used to produce high‐surface‐area perovskite electrocatalysts with high phase purity, minimum surface contamination, and high electrochemical stability. In this study, as‐prepared LaCo 1–x Fe x O 3 perovskite nanoparticles (x=0.2, 0.3, and 0.4) were found to contain a high degree of combustion residuals, and mostly consist of both, stoichiometric and oxygen‐deficient perovskite phases. Heating them at moderate temperature (250 °C) in oxygen could remove combustion residuals and increases the content of stoichiometric perovskite while preventing particle growth. A higher surface crystallinity was observed with increasing iron content coming along with a rise in oxygen deficient phases. With heat treatment, OER activity and stability of perovskites improved at 30 and 40 at.% Fe while deteriorating at 20 at.% Fe. This study highlights spray‐flame synthesis as a promising technique to synthesize highly active nanoscale perovskite catalysts with improved OER activity.