Development of Micro Catalytic Combustor with Pt/Al_2O_3 Thin Films(<Special Issue>Micro Mechanical Engineering)

Catalytic combustion of butane in micro-scale conduits is investigated. Nano-porous alumina formed through anodic oxidation of aluminum is employed for the support of platinum catalyst. Combustion starts at 250℃, and a heat release rate up to 710 MW/m^3 is achieved in a 0.6mm ID tube. It is found that the surface reaction speed is a limiting factor for the overall reaction rate. A prototype silicon-based catalytic combustor is designed and fabricated using MEMS technologies. The Pt/alumina catalyst layer is successfully integrated onto a silicon microchannel, and a Pyrex lid is anodically bonded onto the Si substrate. It is found in a preliminary experiment that the MEMS combustor also works well, but gives somewhat smaller reaction rate due to the thinner catalytic layer.