Deactivation process, electrocatalyst

Conventional heterogeneous catalysis and empiricism could provide a starting point in the selection of electrocatalysts for new unexplored processes for chemical production, energy generation or conservation, and environmental control. However, a fundamental understanding of adsorption characteristics, electrode kinetics, mechanisms, adsorbate-support interactions, and deactivation processes are needed for improved electrocatalyst... 

The kinetics of electrochemical reactions are often modified by the nature of the electrode material, and by the presence of atomic and molecular species either adsorbed on the surface or in the bulk solution [14]. Electrocatalysis is primarily concerned with the study of this phenomenon and, particularly, with the factors that govern enhancements in the rates of redox processes. Implicit in this general statement is the ability of the species responsible for these effects, or electrocatalyst, or the electrode itself, to carry out the reaction numerous times before undergoing possible deactivation. Electrocatalytic processes in which the electrode simply serves as a source or sink of electrons to generate solution phase species that... 

Although Reactions (41)—(44) are usually viewed as electrocatalyst deactivation steps 195, 199, surface reactions of these intermediates with adsorbed [HjO] or [OH] have also been postulated for the overall oxidation process of CH4, CHjOH, HCHO, and HCOOH 81, 206, 207. The presence of certain proposed intermediates such as [COOH], [CjOjH], and... 

The operation of electrocatalysts in an electrolyte and in the presence of an electric field imposes stringent conditions on maintaining activity. Avoiding catalyst aging or deactivation is of great economic importance for the successful application of electrochemical processes. Deactivation can arise because of ... 

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