Mixed-cation perovskite La0.6Ca0.4Fe0.7Ni0.3O2.9as a stable and efficient catalyst for the oxygen evolution reaction

Sergei V. Porokhin, Victoria A. Nikitina, Dmitry A. Aksyonov, Dmitry S. Filimonov, Egor M. Pazhetnov, Ivan V. Mikheev, Artem M. Abakumov

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)

Abstract

The La0.6Ca0.4Fe0.7Ni0.3O2.9perovskite was synthesized using a modified ultrasonic spray pyrolysis technique with sorbitol as the fuel and ozone as the oxidizer, resulting in chemically homogeneous hollow spheres with a specific surface area as high as ~15 m2g-1. The crystal structure and the chemical composition were determined with powder X-ray diffraction, electron diffraction, aberration-corrected scanning transmission electron microscopy, energy-dispersive X-ray mapping, 57Fe Mössbauer spectroscopy, iodometric titration, and X-ray photoelectron spectroscopy. Being employed as a catalyst for the oxygen evolution reaction (OER) in 1 M NaOH, La0.6Ca0.4Fe0.7Ni0.3O2.9demonstrates a mass activity of ~400 A g-1oxideat 1.61 V vs RHE and a low 52 ± 2.6 mv dec-1 Tafel slope without noticeable degradation. The superior activity of La0.6Ca0.4Fe0.7Ni0.3O2.9compared to that of undoped LaFe0.7Ni0.3O3was rationalized by the comparison of DFT-calculated electronic structures. The Ca doping increases Ni and Fe oxidation states, enhances covalency of the Ni/Fe-O bonds, shifts the center of the O 2p band closer to the Fermi level thus decreasing formation energy of the oxygen vacancies, and activates the lattice oxygen mechanism of the OER, which enhances the catalytic activity. Yet, an optimal balance between stability and activity ensures that the thin and stable active layer of Ni-Fe (oxy)hydroxide is supported by the preserved perovskite structure.

Original languageEnglish
Pages (from-to)8338-8348
Number of pages11
JournalACS Catalysis
Volume11
DOIs
Publication statusPublished - 2021

Keywords

  • Lattice oxygen mechanism
  • Oxygen evolution reaction
  • Perovskite
  • Spray pyrolysis
  • Water splitting

Fingerprint

Dive into the research topics of 'Mixed-cation perovskite La0.6Ca0.4Fe0.7Ni0.3O2.9as a stable and efficient catalyst for the oxygen evolution reaction'. Together they form a unique fingerprint.

Cite this