Characterization of a highly sensitive and selective hydrogen gas sensor employing Pt nanoparticle network catalysts based on different bifunctional ligands

A catalytic hydrogen gas sensor of superior sensitivity, selectivity, resolution and dynamic response was developed with catalysts composed of ligand-stabilized Pt nanoparticles. We have characterized different catalysts utilizing the bi-functional ligands trans-1,4-diaminocyclohexane (DACH), 1,5-diaminonaphthalene (DAN), 4,4´´-diamino-p-terphenyl (DATER), benzidine (BEN) and p-phenylene diamine (PDA) for hydrogen gas sensing. A comprehensive evaluation by comparison, with respect to both, structural aspects (TEM and SEM) and gas sensing performance of the 5 types of ligand-linked Pt nanoparticles and non-stabilized Pt nanoparticles was conducted to select the optimized catalysts. From this investigation, DATER-linked Pt nanoparticles appear immensely promising: the sensor is selective to hydrogen and shows extremely high sensitivity, around 400 mV/1% vol., but exhibits no crosssensitivity to methane and ethane. Likewise, sensors with DATER- and DAN-linked Pt nanoparticles can detect down to 0.001 % (10 ppm) alongside 650 ms average response time (t90).