Valence state of elements on the Fe-Ru catalyst surface treated in variousmedia

X-ray photoelectron spectroscopy (XPS) is used to show that Fe and Ru on th e catalyst. surface virtually completely transform into the metallic state during the reduction of the Fe-Ru catalyst. Analysis of the spectra of nitr ogen, which is present in the reduced and activated Fe-Ru catalyst, showed the presence of three N1s signals with the binding energies 400.4, 398.6, a nd 397.4 eV. These bands are assigned to three nitrogen states: NH3, NH and /or NH2, and N-2 (or one of the forms of molecular nitrogen, which is a pre cursor of dissociation), respectively.