Proton Exchange Membrane Fuel‐Cell‐Based Amperometric H₂ Sensor with Pulsed Electrodeposited Electrodes Prepared Using an Ionic Liquid Electrolyte

Abstract

A fuel cell based amperometric H2 sensor with pulsed electrodeposited electrodes has been developed and tested for its performance. Nafion, a commercial proton exchange membrane was used as electrolyte in the sensor. Platinum (Pt) deposited gas diffusion electrode (GDE) based sensing and counter electrodes were prepared by electrodeposition and pulsed electrodeposition methods using 1‐butyl‐3‐methylimidazolium tetrafluoroborate ionic liquid electrolyte. Prior to the electrodeposition, the electrodeposition behaviour of Pt on GDE was studied by cyclic voltammetry, chronoamperometry and chronopotentiometry. The deposition potential of Pt was obtained from cyclic voltammogram. The nucleation and growth behaviour of Pt were examined by chronopotentiometry and chronoamperometry. Electrodeposition and pulsed electrodeposition of Pt on GDE were carried out under the optimized conditions. The prepared electrodes were characterized by field emission scanning electron microscope and gracing incidence X‐ray diffraction. In order to compare the sensor performance, Nafion based amperometric hydrogen sensors were made with both electrodeposited and pulsed electrodeposited Pt on GDE electrodes. The assembled amperometric H2 sensors were tested in the dynamic range of 1–4% of H2/Ar. Pulsed electrodeposited Pt on GDE sensor showed higher sensitivity and better response time than the electrodeposited Pt on GDE sensor.