Rapid and Selective Detection of Trace Hydrogen by Mesoporous SnO2 Anchored with Au–Pd Dual-Atom Sensitizers

Due to weak interactions between hydrogen molecules and sensing materials as well as slow H2 oxidation kinetics, traditional semiconductor metal oxides (SMOs) have limited capability for selective and rapid hydrogen sensing. We propose an innovative strategy to enhance gas-sensing performance by modifying SMOs with atomically dispersed dual noble-metal sensitizers, differing from conventional single-atom or nanoparticle sensitizers. This sensor shows fast response time (1 s), strong resistance to CO, NO, H2S, and SO2 interference, and an ultralow detection limit (70 ppb) toward hydrogen, surpassing single noble-metal modified hydrogen sensors. The excellent sensing performance can be attributed to the synergistic sensitization of atomically dispersed Au/Pd dual catalysts with complementary gas activation properties. The hand-held hydrogen detector, featuring a fast response (<1 s), demonstrates robust early warning capability for H2 leakage. This work introduces an atomically dispersed dual noble-metal sensitization strategy for superior hydrogen sensing, paving the way for hydrogen safety.