Pt-Based Catalytic Microcombustor for Micropower Generation

This paper presents the fabrication and characterization of platinum-based catalytic microcombustor. The platinum catalyst was deposited onto type-304 stainless steel using the wet impregnation method. The stainless steel undergoes controlled conversion coating treatment in sulfuric acid solution to increase the porosity of its surface before the deposition of the platinum catalyst. The scanning electron microscopy result showed that the porosity on the stainless steel surface will depend on the length of treatment time in the sulfuric acid solution. The surface porosity increased as the treatment time increases. The stainless steel surface morphology changed from smooth to ‘cracked-mud’ morphology after treatment in sulfuric acid solution. The treatment time also provide significant effect to the amount of platinum deposited on the stainless steel surface. The energy dispersive x-ray analysis showed that the amount of deposited platinum for 10 seconds of treatment time was 0.68 wt%, whereas those for 20 and 30 seconds were 0.87 wt% and 1.10 wt%, respectively. Liquefied petroleum gas-air combustion result showed that the flame completely submerged inside the microcombustor with a catalyst, whereas portions of flame can be observed at the exhaust for the microcombustor without a catalyst. The minimum air-to-fuel ratios before the combustion blow-out for 10, 20, and 30 seconds of treatment time was 0.5, 0.4, and 0.3 respectively.