Electrochemical Processes for a Sustainable Development
Electrochemical processes have been used for decades in diverse branches of industry such as synthesis of fi ne chemicals, mass production of certain metals such as aluminium or sodium, production of gas, e.g., hydrogen, chlorine or fl uorine, deposition of metals or alloys, treatment of effl uents or power production. Besides these various industrial applications, electrochemical techniques constitute the principle of numerous analytical techniques. At a more fundamental level, they are also used in the study of mass transfer phenomena in liquid media at the contact of a solid surface. The wide spectrum of applications results from two main characteristics of electrochemical systems:
• The electrochemical reaction is a heterogeneous process which thus presents numerous common points with the reaction taking place onto the surface of a catalyst. The electrochemical conversion consists of the sequence of physicochemical processes, e.g., adsorption, reactions at the electrode surface (charge transfer) with possibly chemical reactions, and physical steps as transport and transfer phenomena.