Microhotplate catalytic sensors based on porous anodic alumina: Operando study of methane response hysteresis

• Published in: Sensors and actuators. B, Chemical Vol. 330; p. 129307
• Main Authors: Roslyakov, I.V., Kolesnik, I.V., Evdokimov, P.V., Skryabina, O.V., Garshev, A.V., Mironov, S.M., Stolyarov, V.S., Baranchikov, A.E., Napolskii, K.S.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.03.2021; Elsevier Science Ltd
• Subjects: Aluminum oxide; Catalytic gas sensor; Electric potential; Explosives detection; Flammability; Flammable gases; Hysteresis; Methane; Microhotplate; Operando study; Pd-Pt catalyst; Power consumption; Sensor response hysteresis; Sensors; Thermogravimetry; Voltage; Methane; Microhotplate; Sensor response hysteresis; Operando study; Catalytic gas sensor; Pd-Pt catalyst
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2020.129307

[Display omitted] •Microhotplate catalytic sensors based on anodic alumina supports are prepared.•Methane detection sensitivity reaches 15 mV/vol. % CH4.•Operando X-ray diffraction and thermogravimetry studies are performed.•Hysteresis in sensitivity correlates with Pd oxides content in the Pd-Pt catalyst. Catalytic pellistor-type sensors are widely used for the analytical detection of flammable/explosive gases. Further improvement of the characteristics of the sensors can be achieved by the development of miniature sensing elements based on planar microhotplates, which allows one to decrease the power consumption substantially. Here we demonstrate the microhotplate catalytic sensors based on anodic aluminium oxide supports for methane detection. The sensor response approaches the value of 15 mV/vol. % CH4 at the optimal supply voltage. A wide hysteresis in sensor response is observed during the cycling of the supply voltage. This phenomenon is studied under operando conditions using X-ray diffraction and thermogravimetry. The obtained results have a significant impact on the development of optimal working regimes, and the production of planar catalytic sensors on porous supports.