Crystal Face‐Dependent Behavior of Single‐Atom Pt: Construct of SA‐FLP Dual Active Sites for Efficient NO2 Detection

Abstract The strong potential of platinum single atom (Pt SA ) in gas sensor technology is primarily attributed to its high atomic economy. Nevertheless, it is imperative to conduct further exploration to understand the impact of Pt SA on the active sites. In this study, the evolution of Pt SA on (100)CeO 2 and (111)CeO 2 is examined, revealing notable disparities in the position and activity of surface Pt SA on different crystal planes. The Pt SA in (100)CeO 2 surface can enhance the stability of Ce 3+ and construct a frustrated Lewis pair (FLP) to form a double active site by combining the steric hindrance effect of oxygen vacancies, which increases the response value from 1.8 to 27 and reduce the response‐recovery time from 140–192 s to 25–26 s toward five ppm NO 2 at room temperature. Conversely, Pt SA tends to bind to terminal oxygen on the surface of (111)CeO 2 and become an independent reaction site. The response value of Pt SA ‐(111)CeO 2 surface only increased from 1.6 to 3.8. This research underscores the correlation between single atoms and crystal plane effects, laying the groundwork for designing and synthesizing ultra‐stable and efficient gas sensors.