Potential binding energy

Figure 3.30. For the isothermal transformation of a liquid to a gas (evaporation), the reaction enthalpy AH is a measure of the increase in the potential binding energy A

In order for the primary photoelectron, which is bound to the surface atom with binding energy to be detected ia xps, the electron must have sufficient kinetic energy to overcome, ia addition to E the overall attractive potential of the spectrometer described by its work function, Thus, the measured kinetic energy of this photoelectron, Ej is given by... 

There remains the estimated value of °(H+/H2)vs. UHV based on binding energies for image potential-induced surface states,49 which is,... 

Figure 11.7 confirms that electrochemically induced and controlled O2 backspillover from the support to the metal film surface is the promoting mechanism both in the case of YSZ (Fig. 11.7a) and in Ti02 (Fig. 11.7b). These figures show the Ols spectrum of the Pt film deposited on YSZ and on TiC>2, first under open-circuit conditions (Fig. 11.7aC, 11.7bA) and then under positive current and potential application (Fig. 11.7aB, 11.7bB). Figures 11.7aC and 11.7bC show the difference spectra. In both cases, XPS clearly shows the presence of the O2 double layer, even under open-circuit conditions (Figs. 11.7aA, 11.7bA) and also clearly confirms the electrochemically controlled backspillover of O2 from the YSZ orTi02 support onto the catalyst surface. Note that the binding energy of the backspillover O species is in both cases near 529 eV, which confirms its strongly anionic (probably O2 ) state.31,32...

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