Rational Design of PdPt Nanoalloys Sensitized Mesoporous SnO₂ for High‐Performance Methane Sensing Applications

Abstract Methane (CH₄) serves as a commonly utilized fuel gas in various industrial and everyday settings. Given its flammable, explosive, and greenhouse gas nature, the real‐time monitoring of its concentration in the air holds vital importance across practical applications. The tetrahedral structure of methane molecules features high bond energies, posing a significant challenge for chemical detection over metal oxide‐sensitive layers. In this research, a multicomponent assembly method is used to synthesize ordered mesoporous tin oxide (SnO₂) with uniform large mesopores (≈ 10 nm) and pore wall functionalized with Pd_xPt nanoalloys (≈ 2.5 nm), and due to the unusual C–H bond activation capabilities of Pd_xPt nanoalloys and semiconducting properties of mesoporous SnO₂, the obtained Pd₂Pt@m‐SnO₂ is used to fabricate gas sensors which showcases a wide applicability range in detecting concentrations ranging from 50 to 20 000 ppm at 400 °C, and it yields a substantial CH₄ response of 9.19 (1000 ppm) and an ultralow limit of the detection value of 175.9 ppb. Furthermore, the sensor is successfully incorporated into a portable device, evidencing its capability for accurate CH₄ detection in real‐world scenarios.