Comparative performance analysis of a PdAu resistive hydrogen sensor under aerobic and anaerobic environments

Reliable hydrogen detection is essential for ensuring safety and operational monitoring in emerging hydrogen energy systems. However, sensor performance strongly depends on environmental conditions, particularly the presence of oxygen, which may alter detection mechanisms at low hydrogen concentrations. This work presents a structured experimental evaluation of a PdAu alloy–based resistive hydrogen microsensor operating under both anaerobic and aerobic environments. A comprehensive performance analysis protocol was developed to assess key sensing parameters, including response amplitude, sensitivity, response and recovery times, repeatability, hysteresis, and baseline stability over a range of operating temperatures. The results identify an optimal operating temperature of 50 °C, providing a balanced compromise between sensitivity, stability, and detection kinetics. Under these conditions, the sensor exhibits relative responses exceeding 6%, baseline drift below 0.4%, sensitivity to hydrogen concentration variations of 0.1%, and hysteresis errors below 10%. The detection limits reach approximately 100 ppm in nitrogen and 300 ppm in dry air, highlighting the influence of oxygen on low-concentration hydrogen sensing. These findings demonstrate the potential of PdAu resistive microsensors for hydrogen leak detection and monitoring applications in energy systems, particularly in environments where both inert and oxygen-containing atmospheres may be encountered.