DEVELOPMENT OF EFFECTIVE SENSORS FOR DETECTING PRE-EXPLOSIVE H2 CONCENTRATIONS

We studied the response of catalytic sensors to hydrogen with various types of platinum-group catalysts (Pt, Pd, Ir, Rh, Pt+Pd) in the pre-explosive concentration range. Temperature dependences of sensory response are analysed. Dependences of the sensory response on the applied voltage demonstrates hysteresis behavior that can be explained by the partial transition of the oxides of the platinum group metals into the metallic phase at temperatures above 500 °C and the reverse oxidation of metals if temperature is below 400 °C. Catalytic sensors with Ir and Rh catalysts are more preferable for practical use in the detection of hydrogen.