Mn-ni-co-o spinel oxides towards oxygen reduction reaction in alkaline medium: Mn0.5ni0.5co2o4/c synergism and cooperation

Thabo Matthews, Tarekegn Heliso Dolla, Sandile Surprise Gwebu, Tebogo Abigail Mashola, Lihle Tshepiso Dlamini, Emanuela Carleschi, Patrick Ndungu, Nobanathi Wendy Maxakato

Research output: Contribution to journalArticlepeer-review

10 Citations (Scopus)

Abstract

Mn-doped spinel oxides MnxNi1−xCo2O4 (x = 0, 0.3, 0.5, 0.7, and 1) were synthesized using the citric acid-assisted sol–gel method. The Mn0.5Ni0.5Co2O4 (x = 0.5) supported on carbon nanosheets, Mn0.5Ni0.5Co2O4/C, was also prepared using the same method employing NaCl and glucose as a template and carbon source, respectively, followed by pyrolysis under an inert atmosphere. The electrocatalytic oxygen reduction reaction (ORR) activity was performed in alkaline media. Cyclic voltammetry (CV) was used to investigate the oxygen reduction performance of MnxNi1−xCo2O4 (x = 0, 0.3, 0.5, 0.7, and 1), and Mn0.5Ni0.5Co2O4 was found to be the best-performing electrocatalyst. Upon supporting the Mn0.5Ni0.5Co2O4 on a carbon sheet, the electrocatalytic activity was significantly enhanced owing to its large surface area and the improved charge transfer brought about by the carbon support. Rotating disk electrode studies show that the ORR electrocatalytic activity of Mn0.5Ni0.5Co2O4/C proceeds via a four-electron pathway. Mn0.5Ni0.5Co2O4/C was found to possess E1/2 (V) = 0.856, a current density of 5.54 mA cm−2, and a current loss of approximately 0.11% after 405 voltammetric scan cycles. This study suggests that the interesting electrocatalytic performance of multimetallic transition metal oxides can be further enhanced by supporting them on conductive carbon materials, which improve charge transfer and provide a more active surface area.

Original languageEnglish
Article number1059
JournalCatalysts
Volume11
Issue number9
DOIs
Publication statusPublished - Sept 2021

Keywords

  • Alkaline fuel cells
  • Electrocatalyst
  • Oxygen reduction reaction
  • Spinel oxide

ASJC Scopus subject areas

  • Catalysis
  • General Environmental Science
  • Physical and Theoretical Chemistry

Fingerprint

Dive into the research topics of 'Mn-ni-co-o spinel oxides towards oxygen reduction reaction in alkaline medium: Mn0.5ni0.5co2o4/c synergism and cooperation'. Together they form a unique fingerprint.

Cite this