Cobalt Manganese Oxides as Oxygen Evolution Catalysts in Acidic Media

Here, we propose a study of Co and Mn K-edge XAS and EXAFS spectra of cobalt manganese oxide spinel catalysts for the oxygen evolution reaction (OER) in acidic conditions. Using a combination of an established flow cell setup and an industrially relevant MEA cell, operando measurements of gas-evolving reactions can be conducted under realistic operating potentials and current densities. This allows identification of intermediate phases in the catalyst and understanding of its structural evolution. Through interpretation of the pre-edge and rising edge features in XANES spectra, and the evolution of M-O and M-M (where M could be Co or Mn) coordination environments from FT-EXAFS spectra fitting, we aim to address the key question: how do the Co and Mn oxidation states and coordination environments evolve with potential in an acidic electrolyte?