Pt‐Pd Nanoalloys Functionalized Mesoporous SnO2 Spheres: Tailored Synthesis, Sensing Mechanism, and Device Integration

Abstract Methane (CH 4 ), as the vital energy resource and industrial chemicals, is highly flammable and explosive for concentrations above the explosive limit, triggering potential risks to personal and production safety. Therefore, exploiting smart gas sensors for real‐time monitoring of CH 4 becomes extremely important. Herein, the Pt‐Pd nanoalloy functionalized mesoporous SnO 2 microspheres (Pt‐Pd/SnO 2 ) were synthesized, which show uniform diameter (≈500 nm), high surface area (40.9–56.5 m 2 g −1 ), and large mesopore size (8.8–15.8 nm). The highly dispersed Pt‐Pd nanoalloys are confined in the mesopores of SnO 2 , causing the generation ofoxygen defects and increasing the carrier concentration of sensitive materials. The representative Pt 1 ‐Pd 4 /SnO 2 exhibits superior CH 4 sensing performance with ultrahigh response ( R a /R g = 21.33 to 3000 ppm), fast response/recovery speed (4/9 s), as well as outstanding stability. Spectroscopic analyses imply that such an excellent CH 4 sensing process involves the fast conversion of CH 4 into formic acid and CO intermediates, and finally into CO 2 . Density functional theory (DFT) calculations reveal that the attractive covalent bonding interaction and rapid electron transfer between the Pt‐Pd nanoalloys and SnO 2 support, dramatically promote the orbital hybridization of Pd 4 sites and adsorbed CH 4 molecules, enhancing the catalytic activation of CH 4 over the sensing layer.