Strong Metal–Support Interaction Induces Dual Reaction Sites for Ultrasensitive and Stable NO₂ Detection in Extreme Environments

Abstract The tripartite combination of a high density and stability of surface reaction sites, complemented by the longevity and efficient transfer of interface carriers, along with the effective adsorption and activation of target gas molecules, jointly determines the efficiency of chemiresistors. In this work, the strong metal–support interaction (SMSI) of Pt─Ce 3+ is formed by the NaBH 4 reduction method and thus prepares metal‐dynamically stable Pt NR ─CeO 2 with Pt─Ce 3+ and Pt─Pt reaction sites. The formation of SMSI induces the recombination of the chemical structure of the CeO 2 surface causing the localization of electron‐rich Ce 3+ , which greatly increases the charge concentration at the interface. The experimental findings of the strong interaction of Pt─Ce 3+ bonding and the catalytic effect of Pt optimized the adsorption mode of Pt NR ─CeO 2 on target gas, which maintains stable catalytic activity at 20–500 °C and achieving a notable detection response value of 1.43 for 20 ppb NO 2 . This work offers fresh insights into designing stable oxide chemiresistors with efficiency and stability by customizing reaction sites at the atomic level.