Solid-state hydrogen sensor based on acid-doped polybenzimidazole

A solid-state potentiometric hydrogen sensor for hydrogen determination in air is described. The device incorporates a protonic polymer electrolyte based on polybenzimidazole, an E-TEK gas diffusion electrode as sensing electrode and an Ag-AgCl electrode as reference electrode. The sensing mechanism of E-TEK can be explained by the mixed potential model. The stability of the reference system is demonstrated. The reference system is assumed to operate properly because of the existence of a thin hydrated layer containing chlorine ions. The sensor performances are reported.