V.  Pfeifer, Jones, T. E., Vélez, J. J. Velasco, Arrigo, R., Piccinin, S., Hävecker, M., Knop-Gericke, A., and Schlogl, R., ?In situ observation of reactive oxygen species forming on oxygen-evolving iridium surfaces?, Chemical Science, vol. 8, pp. 2143-2149, 2017.