STUDY OF THE INFLUENCE OF FLAMELESS CATALYTIC COMBUSTION OF HYDROGEN ON PLATINUM GROUP CATALYSTS ON PARAMETERS OF THERMAL CATALYTIC SENSORS

An investigation was conducted on the response of hydrogen catalytic sensors with platinum group catalysts (Pt+3Pd, Pt, Pd, Ir, and Rh) at room temperature. It was shown that the reaction of flameless catalytic combustion of hydrogen on Pt and Pt+3Pd catalysts occurs at a temperature of 20 ºC, which is manifested in the spontaneous heating of the sensitive element of the catalytic sensor and an increase in the resistance of the microheater. For the first time, the temperature of the microheater was measured, and it was shown that the temperature increased by 99 ºC and 84 ºC in the gas mixture containing 0.96% vol. of hydrogen for Pt and Pt+3Pd catalysts, respectively. A method for measuring the hydrogen concentration with a catalytic sensor without applying a heating voltage has been proposed.