Pd Decoration with Synergistic High Oxygen Mobility Boosts Hydrogen Sensing Performance at Low Working Temperature on...

Pd-based materials have received remarkable attention and exhibit excellent H₂ sensing performance due to their superior hydrogen storage and catalysis behavior. However, the synergistic effects originated from the decoration of Pd on a metal oxide support to boost the sensing performance are ambiguous, and the deep investigation of metal support interaction (MSI) on the H₂ sensing mechanism is still unclear. Here, the model material of Pd nanoparticle-decorated WO₃ nanosheet is synthesized, and individual fine structures can be achieved by treating it at different temperatures. Notably, the Pd-WO₃-300 materials display superior H₂ sensing performance at a low working temperature (110 °C), with a superior sensing response (R_a/R_g = 40.63 to 10 ppm), high sensing selectivity, and anti-interference ability. DFT calculations and detailed structural investigations confirm that the moderate MSI facilitates the generation of high mobility surface O₂^- (ad) species and a proper ratio of surface Pd⁰-Pd²⁺ species, which can significantly boost the desorption of intermediate PdH species at low temperatures and contribute to enhanced sensing performance. Our work illustrates the effect of MSI on sensing performance and provides insight into the design of advanced sensing materials.