Highly sensitive hydrogen detection using curvature change of wireless-electrodeless quartz resonators

Abstract

We propose a hydrogen detection method using a thin quartz resonator with a palladium thin film on its single side, which absorbs hydrogen, resulting in the film expansion and geometry change of the resonator, shifting the resonant frequency. Because the resonator is driven in a wireless manner, the other resonator side can remain electrodeless, enhancing the geometry change and then the detection sensitivity. The detection limit is 1 ppm or less. We also investigate the reaction kinetics between palladium and hydrogen through the temperature dependence of the reaction velocity constant, yielding the activation energy of 0.372 ± 0.003 eV. This is close to the activation energy for the hydrogen-atom transition from the surface to subsurface states, indicating that the adsorption reaction is dominated by the transition rather than the bulk diffusion in palladium.