A gated electrode structure for altering a potential and electric field in an electrolyte near at least one working electrode is disclosed. The gated electrode structure may comprise a gate electrode biased appropriately with respect to a working electrode. Applying an appropriate static or dynamic (time varying) gate potential relative to the working electrode modifies the electric potential and field in an interfacial region between the working electrode and the electrolyte, and increases electron emission to and from states in the electrolyte, thereby facilitating an electrochemical, electrolytic or electrosynthetic reaction and reducing electrode overvoltage/overpotential.