Electrochemical Electron Transfer: From Marcus Theory to Electrocatalysis - Fuel Cell Catalysis: A Surface Science Approach - page 46

Figure 2.13 Density of states of a level positioned at the center of a d-band for the cases of a
strong and a weak interaction. The d-band is centered at 1 ¼ 0 and has a half-width of 2 eV.
(a) D d ¼ 0.3 eV; (b) D d ¼ 3eV.
acquires a little density of states at the energy of the d-band; for a strong interaction, the
level is again split into an antibonding orbital, which has been shifted upwards, and a
bonding orbital, which has been shifted downwards. However, the two levels do not
have equal weight. For a more detailed discussion, we refer to the paper by [Newns,
1969]. This splitting of an orbital by a strong interaction with a narrow d-band is of
central importance for electrocatalysis, as we shall see below.
Figure 2.14 Density of states of a level originally positioned at 1 ¼ 1 : 2 eV above a d-band,
for the cases of a strong and a weak interaction. The position of the d-band is as in Fig. 2.13.
(a) D d ¼ 0 : 3 eV; (b) D d ¼ 3eV :