Nickel-iron electrocatalysts exhibit activities for oxygen evolution which are notably higher than those of their end-members, but neither the composition of maximum activity nor the source of enhanced activity is well-established. In our work, we aim to understand how the presence of iron influences the electrocatalytic activity of Ni-Fe. Ni-Fe films are electrochemically deposited onto gold substrates, and confocal Raman microscopy is employed to characterize the catalysts, in-situ, as the oxygen evolution reaction is being driven, to gain insight into the relationship between the catalyst chemistry/structure and catalyst activity. The oxygen evolution activity reaches a maximum for films with approximately 50% Fe content; at this composition, the current density for oxygen evolution is increased by two orders of magnitude compared to Ni and almost four orders compared to Fe. Raman spectra reveal that, under oxygen evolution conditions, NiOOH and ?-Fe2O3/FeOOH phases are observed in the Ni-Fe films.

In-situ characterization of nickel-iron catalysts for the oxygen evolution reaction

245th National Meeting (2013)

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