Pd Nanoparticle/Pd/Al2O3 Resistive Sensor for Hydrogen Detection in a High-Temperature Environment

An Al 2 O 3 thin film is deposited on the interdigitated electrodes to fabricate a resistive hydrogen sensor. In addition, the Pd nanoparticles (NPs)/Pd film by vacuum thermal evaporation system on the Al 2 O 3 film acts as catalytic metals for hydrogen detection. Due to the Pd NPs with an increased surface area to volume ratio as well as the spill-over effect, the catalytic activity could be improved to enhance the gas sensing performance. The experimental results showed that the sensing response ratio is 14.4% in 1000 ppm H 2 /air at 300 °C, which is suitable for high-temperature hydrogen detection. The studied Pd NPs/Pd/Al 2 O 3 resistive sensor exhibits the advantages of in high-temperature operation, simple structure, easy fabrication process, and relatively low cost.