Long-term stability of chemiresistive gas sensors is essential for their use in industrial and residential safety and air-quality monitoring systems. Incorporation of noble metals into the gas sensors has been proved to be an effective strategy to enhance their sensitivity and selectivity. However, noble metal particles are prone to poisoning, resulting in catalyst deactivation. Atomically dispersed supported metal catalysts constitute a new class of materials that contains isolated individual atoms or synergistically coupled few-atom ensembles dispersed on, and/or coordinated with the surface atoms of appropriate solid supports. Examples include noble metals such as Pd and Pt on metal oxides, such as tin oxide. These materials have emerged as a rapidly developing class of catalysts offering the advantage of the most efficient use of noble metals combined with unique properties considerably different from their conventional nanoparticle equivalents. These include excellent selectivity for gas adsorption, electron transport and improved resistance to poisoning and coke formation. Herein, we aim to investigate the potential of atomically dispersed catalysts supported on metal oxides for the fabrication of robust chemiresistive gas sensors for in-door air quality monitoring. Towards this aim, we have successfully synthesized atomically dispersed Pd catalysts supported on tin (IV) oxide, SnO2. The resulting materials exhibit exceptional sensitivity and selectivity towards carbon monoxide. Current efforts aim to elucidate their gas sensing mechanisms through detailed structural, chemical, electrical and optical characterizations. These insights will aid in developing guideposts for further improvements in these sensors and their broader utilization in a variety of applications.
Project currently funded by: Industry Sponsor