Study of Pd Membrane Electrode in Solid Electrolyte Hydrogen (Isotopes) Sensor for Application to Liquid Blankets

Abstract

On-line measurement of hydrogen isotopes in corrosive environments is essential for the development of liquid blanket systems for fusion reactors. In the present study, a Pd membrane electrode for a solid electrolyte hydrogen sensor was developed. An electrode fabricated on the sensor surface was metallurgically analyzed and was found to be a compact layer with much lower porosity than conventional Pt electrodes. This compact electrode can serve as a protective layer against corrosion of the sensor material during measurement. The response and stability of the sensor with the Pd membrane electrode was investigated in an Ar-hydrogen gas mixture environment. The electromotive force of the sensor with the Pd compact electrode agreed with a theoretical calculation, assuming the same three-phase boundary as in the sensor with a porous Pt electrode.