Low Temperature Methane Combustion Catalysts for Pellistors Investigated By Simultaneous Thermal Analysis

摘要

The early detection of explosive gas atmospheres is highly relevant for industrial process measurement technology and avoids the endangerment of people. In the field of safety technology, catalytic combustion sensors, so-called "pellistors", are used to detect flammable gases such as hydrocarbons or hydrogen. Pellistor sensors measure the heat produced from catalytic oxidation of the gas by detecting the resistance alteration of a Pt-based heater induced by temperature changes using a Wheatstone bridge circuit. The heat generated is related to the kind and concentration of gas by specific combustion enthalpy. The major advantages of catalytic sensors are simple operation principle, easy installation and calibration. However, state-of-the-art pellistors have some disadvantages, such as high operation temperatures of over 400°C, high-power consumption and high susceptibility to catalyst poisons. High-power consumption limits the usage of pellistors in mobile applications because of the short battery lifetime. Reducing operating temperature will contribute to decrease the power consumption.