The data for 623 K over Ru(1013). For Ru, the spectra shown are the summation of the entire time series. Note the difference in y -axis scale in the spectral figures. The formation and depletion of nitride on the surface of each catalyst are shown as a function of time. At the top, the N 2 gas is introduced with a total pressure of 150 mbar and spectral collection begins. Then, after the nitride begins to stabilize, H 2 gas is introduced immediately in a 1:1 ratio with N 2 with a total pressure of 300 mbar, reducing the surface within the frame of the detector. Next to each time series are example spectra normalized to the background, with a grey arrow showing the frame it represents.
