Calorimetric Thermoelectric Gas Sensor for the Detection of Hydrogen, Methane and Mixed Gases

Abstract

A novel miniaturized calorimeter-type sensor device with a dual-catalyst structure was fabricated by integrating different catalysts on the hot (Pd/θ-Al2O3) and cold (Pt/α-Al2O3) ends of the device. The device comprises a calorimeter with a thermoelectric gas sensor (calorimetric-TGS), combining catalytic combustion and thermoelectric technologies. Its response for a model fuel gas of hydrogen and methane was investigated with various combustor catalyst compositions. The calorimetric-TGS devices detected H2, CH4, and a mixture of the two with concentrations ranging between 200 and 2000 ppm at temperatures of 100–400 °C, in terms of the calorie content of the gases. It was necessary to reduce the much higher response voltage of the TGS to H2 compared to CH4. We enhanced the H2 combustion on the cold side so that the temperature differences and response voltages to H2 were reduced. The device response to H2 combustion was reduced by 50% by controlling the Pt concentration in the Pt/α-Al2O3 catalyst on the cold side to 3 wt%.

High Performance Thermoelectric Materials: Progress and Their Applications

“…[420] Thick film NiO-based H 2 sensors have also been investigated via Li doping and using different oxide layers [422] and substrates, [423] which show reasonable sensing properties at room temperature with noise-free voltage signals. [421] Moreover, a double AuPtPd/SnO 2 and Pt/Al 2 O 3 catalyst [428] and Au/SnO 2 -Co 3 O 4 [429] (Figure 16b,c) on a micro-TE sensor was used for CO gas sensing; porous alumina-based sensors were developed for hydrocarbon; [430] dual-catalyzed Pd/θ-Al 2 O 3 and Pt/α-Al 2 O 3 system were able to detect H 2 and CH 4 , [431] which can be used in monitoring the combustion of fuel gas in industrial furnaces. [421] Moreover, a double AuPtPd/SnO 2 and Pt/Al 2 O 3 catalyst [428] and Au/SnO 2 -Co 3 O 4 [429] (Figure 16b,c) on a micro-TE sensor was used for CO gas sensing; porous alumina-based sensors were developed for hydrocarbon; [430] dual-catalyzed Pd/θ-Al 2 O 3 and Pt/α-Al 2 O 3 system were able to detect H 2 and CH 4 , [431] which can be used in monitoring the combustion of fuel gas in industrial furnaces.…”

Human intestinal gas measurement systems: in vitro fermentation and gas capsules

“…The principle of calorimetric platforms is based on either heat evolution from the catalytic oxidation of gas species at high temperature (catalytic bead sensor) or heat dissipation into gas species due to their differing thermal conductivities (thermal conductivity sensor) measured by platinum resistance-temperature detectors [37,38]. The former, however, is unsuitable for anaerobic environment as it needs high ambient oxygen for catalytic reactions.…”

Влияние водорода на термоэлектрический сигнал напряжения в слоистой структуре Pt/WO-=SUB=-x-=/SUB=-/6H-SiC/Ni/Pt

“…Это явление используется для детектирования H 2 в O 2 -содержащих газовых смесях специальными термоэлектрическими сенсорами [4]. Такие сенсоры обладают хорошими техническими характеристиками, но термоэлемен-ты и катализаторы имеют специальную архитектуру и относительно большие (миллиметровые) размеры, что создает проблемы их встра-ивания в многофункциональные датчики, изготавливаемые на одном чипе [5]. Представляет научный и практический интерес исследовать проявление эффекта термоэдс при функционировании тонкопленочных структур, создаваемых на монокристаллических подложках SiC, а также выявить возможность применения этого эффекта для регистрации H 2 .…”