Electrochemical hydrogen isotope sensing via the high-temperature proton conductor CaZr0.90In0.10O3−α

The electromotive force (EMF) behavior of the hydrogen isotope cell using high-temperature proton conductors has been investigated. In the present study, the EMFs for H2–D2 mixtures and those for H2–D2 mixtures diluted with argon against the H2 and D2 reference gases were measured for an electrochemical cell using a proton-conducting electrolyte of CaZr0.90In0.10O3−α. The theoretical equation for the hydrogen isotope cell was derived and compared to the measured EMFs to confirm its validity. The EMF of the cell can determine the atomic molar fraction of the hydrogen isotopes for gases in which the total pressures of the hydrogen isotopes are known.