Resolving ruthenium: XPS studies of common ruthenium materials

X-ray photoelectron spectroscopy (XPS) utilising monochromatic Al K radiation has been employed to study metallic ruthenium and the catalytically and technologically important ruthenium compounds RuO2, RuCl3, Ru(NO)(NO3)(3) and Ru(AcAc)(3). The results improve on the accuracy of already published Ru(3d) binding energies, expand known Ru(3p) binding energies and also report spin-orbit splitting for the core levels. For RuO2, the difference between anhydrous and hydrated samples is explored, and the effect on curve fitting such spectra is discussed. Analysis of RuCl3 has allowed, for the first time, the positive identification of Ru(OH)(3) by XPS. Copyright (c) 2015 John Wiley & Sons, Ltd.