Combustor of ceramic Pt/alumina catalyst and its application for micro-thermoelectric hydrogen sensor

A combustor of Pt/alumina catalyst was developed for the integration on a micro-thermoelectric hydrogen sensor (μ-THS) with a dispenser technique. The Pt/alumina catalyst was deposited on Si substrate and the hydrogen/air mixture gas was flowed to test the combustion performance. The temperature difference, developed by the heat generated from hydrogen oxidation on the catalyst, between the catalyst surface and the Si substrate showed its maximum at the Pt content of 40 wt.% in the catalyst. The effect of the catalyst size on the thermoelectric voltage (ΔVs) of μ-THS was investigated. The catalyst (ϕ = 0.8 mm) smaller than the membrane developed the highest ΔVs because of its good thermal insulation. For the gas mixture of hydrogen/air, the μ-THS showed a wide range of hydrogen detection, 50 ppm-3%, with the ΔVs of 0.03-31.74 mV, respectively, at room temperature.