In Situ Cw ESR Study on Redox Behavior and Phase Heterogeneity in A-Site-Deficient Lanthanum Iron Manganite Perovskite Catalysts

• DOI: 10.1021/acs.jpcc.4c08262
• Publication Date: 2025-04-07T14:04:02Z
• Authors: Zohreh Asadi; Asghar Mohammadi; Thomas Ferdinand ...; Ralf Feyerherm; Roham Talei; Nicolas Bonmassar; Wiebke Riedel; Simon Penner; Thomas Risse
• Keywords: Lanthanum manganite; Manganite; Lanthanum

Temperature-dependent in situ continuous wave (cw) electron spin resonance (ESR) measurements are used for investigating changes magnetization upon reduction and reoxidation La-deficient La x Fe0.7Mn0.3O3 (x < 1) samples to advance the understanding of structural chemical these materials where A-site deficiency was shown affect catalytic performance. For defect-rich mixed perovskites with ferromagnetic ordering, magnetic properties as characterized by cw ESR spectroscopy sensitive probes materials. To this end, spectra observed a redox cycle H2- O2-containing atmospheres not only show that were XRD but also provide evidence heterogeneity phases, which notably depends on samples. This demonstrates potential such investigations obtaining information complementary other methods emphasizes sensitivity probed elucidate complex perovskite While results lack indication presence heterogeneity, STEM compositional between grains an additional phase, one Importantly, different phases exhibit distinct responses reducing (re)oxidizing indicating sample lower facilitated reaction under conditions at low temperatures overall higher stability. Both effects expected reactivity reactions. Thus, new insights can enhance effect reactions considered be important activity systems.