Boosting Room Temperature Sensing Performances by Atomically Dispersed Pd Stabilized via Surface Coordination

The urgent requirement of monitoring air pollution worldwide evokes intensive research interest in developing chemiresistive gas sensing techniques. To overcome the limits in sensitivity and selectivity of room temperature (RT) chemiresistive sensing materials, a new strategy using single-atom catalysts (SACs) via surface coordination is proposed. As a proof-of-concept, single Pd atoms on TiO₂ (Pd₁-TiO₂) possess high efficiency in generating adsorbed O₂^- as well as high activity and selectivity in catalyzing CO oxidation at RT. As a result, Pd₁-TiO₂ shows record high sensitivity among the reported RT sensing materials, which is even comparable to those of the best materials working at high temperature. It also provides an approximately 1 order of magnitude lower limit of detection than the best CO sensing materials. Moreover, Pd₁-TiO₂ presents high selectivity toward 12 kinds of interference gases. This work not only paves a way to design high-performance RT gas sensing materials but also extends the application of SACs.