Palladium Nanoparticle-Based Catalytic Thermopiles for ppb-Level, Subsecond Detection of Acetylene Gas.

Yang, Jingjing; Jia, Hao; Zhang, Haoran; Li, Ming; Li, Jun; Xu, Pengcheng; Li, Xinxin · Nano Lett · 2026

basic_science · Level V

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Abstract

Highly sensitive and rapid detection of trace acetylene (C<sub>2</sub>H<sub>2</sub>) gas is crucial for industrial safety but challenging for existing sensors. Herein, we present a catalytic thermopile-based C<sub>2</sub>H<sub>2</sub> sensor, combining the lowest detection limit and fastest response time/recovery time among reported C<sub>2</sub>H<sub>2</sub> sensors. Facilitated by Pd NPs@Al<sub>2</sub>O<sub>3</sub> (∼3.5 nm in diameter) decorated on the specially engineered differential thermopiles, the sensors can detect the C<sub>2</sub>H<sub>2</sub> concentration down to 5 ppb. The sensors also exhibit the fastest response/recovery time of 0.34/0.40s. The structural design allows a power consumption of only 27.2 mW at 340 °C and a temperature variation of just ∼1.2%, surpassing reported thermopile sensors. Combining the neuroevolution potential (NEP) and multiphysics modeling, we reveal the mechanism of Pd NP-catalyzed cascade bond-breaking and exothermic reaction of C<sub>2</sub>H<sub>2</sub> molecules in oxygen from atomic-scale and energy perspective. This study highlights the potential of noble nanoparticle-based catalytic thermopiles for high-performance C<sub>2</sub>H<sub>2</sub> detection in various industrial applications.