Driving a reaction electrically
An electrolytic cell receives energy from an external source to drive an otherwise nonspontaneous overall reaction under the chosen conditions. Oxidation occurs at the anode and reduction at the cathode. Electron flow through the external circuit and ion motion in the electrolyte complete the electrical process.
Solutions and molten salts
Molten salts and aqueous solutions provide different ionic environments. In water, the solvent and several dissolved species may participate in electrode reactions, so the solute’s name alone does not determine the products. Electrode materials, concentrations and applied voltage also influence which processes become important.
References: [1]
Roles within water electrolysis
Water electrolysis produces hydrogen and oxygen while electrolytes and separators organize ion transport and product separation. Proton-exchange, alkaline and solid-oxide systems use different conducting media and ions. Their temperature ranges and engineering arrangements consequently differ rather than representing one identical cell enlarged to different sizes.
References: [2]
From transferred charge to products
Transferred charge is stoichiometrically related to ideal conversion, while side reactions, overpotentials and resistance affect practical yields and energy use. Metal extraction and plating exploit electrode transformations. Scaling them requires coordinated electrical, thermal and material management beyond merely demonstrating that a reaction can occur.