Some Aspects of Benzene Hydrogenation

In the two previous sections, evidence has been presented concerning the chemisorbed states formed when benzene interacts with metal surfaces. It is not the intention in this Section to discuss benzene hydrogenation in detail, but rather to enquire whether studies of this hydrogen-addition reaction provide information about the chemisorbed state of benzene. 

The question to be asked is this do the processes of benzene hydrogenation and of hydrogen exchange in benzene involve common intermediates, and in particular do these processes share a common form of chemisorbed benzene If the answer is in the affirmative, then the relevant surface species are described in Section II. 

Activation Energies for Hydrogenation, and First Ionization Potentials, for some Aromatic Hydrocarbons 

Hydrocarbon Ionization potential -(eV) Activation energy (kcal mole-1)  

Kubicka further reported that the specific activities of the metals for benzene hydrogenation fell in the sequence Ru Pt Tc Pd Re. We note that, for the elements of the second transition series, the maximum activity was observed for the element of group VIIIi (group VIII2 was not studied). This should be compared with the results in Fig. 4 which show that the activities for the exchange reaction pass through a maximum at 

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