Challenges in hydrogen quantification using Kelvin probe technique at different levels of relative humidity
Sprache des Titels:
Abstract Kelvin probe-based contact potential measurements
were conducted with in situ electrochemical hydrogen loading of a Pd membrane with a thickness of 100 ?m.
The theoretical basis of diffusion coefficient calculation based on measured response time of potential drop,
arising from hydrogen arriving at the detection side of the Pd membrane, was discussed. In situ hydrogen loading
was also utilized for insertion of different amounts of hydrogen into the Pd sample while monitoring the resulting
contact potential difference changes. Measurement of contact potential difference at different final values of
hydrogen concentration in the Pd membrane was performed at various atmospheric conditions, focusing in this work on
increasing relative humidity (4 to 85% rH). Moreover, the effect of humidity changes on hydrogen effusion kinetics
at room temperature and low oxygen content (<1%) was studied.