Kinetics of Hydride Formation and Decomposition

When we deal with the kinetics of hydride reactions we have to be aware that hydride thermodynamics cannot be properly formulated without taking into account the (relative) immobility of the metal component. This immobility can sometimes render the interpretation of the experimental reaction kinetics ambiguous. With this difficulty in mind, let us outline concepts which describe the kinetics of hydride formation and decomposition. An extensive account, including a first order phenomenological treatment, has been given by [P.S. Rudman (1983)]. The conceptual framework for a more rigorous discussion is found in, for example, [G. B. Stephenson (1988)]. 

however, a thin passivating MeO film covers the surface, stochastic nucleation of active sites for the permeation of H and hydride formation occurs. Such a process can be described phenomenologically as outlined in Section 6.2.3 by 

We have already pointed out that hysteresis is observed to occur dining a reaction cycle (Me (H) + H2 MeH ). In addition, it is sometimes found that despite the high H mobility, hydrogenation comes to a stop before the reactants are completely 

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