A standard hydrogen electrode is an electrode that is used as a reference for half-cell potential reactions. Scientists can use standard hydrogen electrodes to determine the basis for which they need to calculate standard cell potentials for other electrode types.
The cell potential of a standard hydrogen electrode is zero. For this reason, standard hydrogen electrodes can be used in various concentrations to act as a reference for other elemental electrodes. A standard hydrogen electrode is composed of a 1.0 molar hydrogen solution with a large piece of platinized platinum. The half-cell potential reaction is started, and hydrogen gas is created. The concentrations of the hydrogen gas and hydrogen solution are measured and act as a comparison for other half-cell potential reactions.