Single-atom catalysts as Frontier materials for advanced gas sensors

Abstract

Single-atom catalysts (SACs) have attracted wide interest in the field of gas sensing, owing to their high atomic utilization efficiency, distinctive electronic structures, and exceptional catalytic performance. Gas sensing is a typically heterogeneous catalytic process, and SACs offer an innovative strategy to modulate and enhance this process. Although SAC-based gas sensors demonstrate considerable potential for performance improvement, the technology is still in its nascent stages of development. This review systematically summarizes recent progress in SAC materials for gas sensing applications, with a focus on synthesis methodologies, underlying sensing mechanisms, and performance evaluation across supporting substrates. Key synthesis approaches such as impregnation, atomic layer deposition, and photochemical strategies are examined, along with mechanistic discussions centered on electron transfer and adsorption–desorption processes. The pivotal role of support materials, including metal oxides and carbon-based substrates, on the sensing behavior is also discussed. Finally, we highlight persistent challenges concerning the stability and selectivity, and propose prospective research directions to facilitate the practical implementation of SACs in advanced gas sensing technologies.