A Reference Electrode System for Electrochemical Measurements in Pure Water

A reference hydrogen electrode systems is constructed by employing a strip of proton‐type Nafion membrane as an ion‐conducting “bridge” to connect a reversible hydrogen electrode (RHE) in an acidic solution to an electrochemical system using pure water as electrolyte, in which the working electrode (WE) is placed. Using such a reference electrode system, the potential at the “WE/pure water” interface is equal to the equilibrium hydrogen electrode potential in pure water when the potential difference between RHE and WE is zero, irrespective of the pH value of the acidic solution in the RHE compartment. The accuracy and reproducibility of the WE potential measurements are within 1–2 mV.