Fabrication and performance test of catalytic micro-combustors as a heat source of methanol steam reformer

Two different types of H2 catalytic micro-combustors were fabricated and evaluated as a heat source of methanol steam reformer through MEMS fabrication technology with photosensitive glass wafers. In a packed-bed micro-combustor design, ceramic foam coated with Pt was the catalyst bed. In the thin-film-coated combustor, Al2O3 was used as catalyst supports and coated on the combustion chamber wall. Pt was coated on the Al2O3 thin-film, which was constructed on the wall. The preparation of Al2O3 coating solution and coating process was set up based on sol–gel method. Both combustors had a combustion chamber whose height was 1 mm and the external volume of combustors was 1.8 cm3. Catalytic combustion of H2 was stable with both combustors. H2 conversions were over 90% for packed-bed micro-combustor and over 99% for Pt/Al2O3 coated micro-combustor. Both combustors burned 80 ml/min of H2. The catalytic micro-combustors fabricated were applicable to the methanol steam reforming system for 20 W level PEMFC.