1. Thermodynamic and kinetic aspects

Electrochemical reactions involve not only the chemical transformation of reactants into products, but also the exchange of electrons between different chemical species. They obey the laws of thermodynamics, but electrical energy must be taken into account when formulating them. When an electrochemical reaction evolves, it obeys kinetic laws that must also take account of the system's electrical variables. In the following paragraphs, we review the thermodynamic and kinetic concepts specific to electrochemical reactions, with particular reference to the case of water electrolysis.