Development of Microreactions for Applications to Thermochemical Reactors and Miniaturized Fuel Cells

开发了具有水蒸气重整催化反应和除钴膜功能的燃料电池微反应器系统。本研究新获得了以下结果。(1)开发了用于制造微通道和修改通道壁的技术，使用各种耐高温和耐腐蚀性化学品的基底。(2)开发了用金属催化剂涂覆微通道的技术。(3)将微通道催化反应器与四极杆质谱仪相结合，建立了一套高效筛选催化剂的系统。(4)将微型加热器和薄膜温度传感器集成在微通道催化反应器中。由此制备了热自支撑微反应器。(5)将微加热器与泵相结合，研制了一种硅基液体蒸发器。该泵是使用三个耐热压电元件制备的，并显示出足够的容量，用于将甲醇送入小型化燃料电池。(6)甲醇的蒸汽重整产生高浓度的CO，这是一种严重的催化剂毒物。为了将CO浓度降低到10 ppm的水平，开发了耐温无机膜（沸石和钯）。分子筛膜作为一种高效的CO氧化反应器，钯膜表现出很高的H_2/CO选择性。

Microreactor systems with functions of catalytic reaction of steam reforming and membranes for Co removal were developed for use in fuel cell systems. The following results were newly obtained in this study.(1) Techniques for fabricating microchannels and modifying channel walls were developed, using various substrates which were resistant to elevated temperature and corrosive chemicals.(2) Techniques for coating the microchannels with metal catalysts were developed.(3) A system which enabled to select proper catalysts efficiently was developed by combining the microchannels catalytic reactors and a quadropole mass spectrometer.(4) A microchannel catalytic reactor was systemized with a miniaturized heater and thin film temperature sensors. Thus a thermally self-supporting microreactor was prepared.(5) A liquid evaporator was developed by combining a pump and a microheater on a silicon substrate. The pump was prepared using three thermally resistant piezoelements and showed a capacity enough for feeding methanol to miniaturized fuel cells.(6) Steam reforming of methanol produces CO, which is a severe catalyst poison, at a high concentration. In order to decrease CO concentration to a level of 10 ppm, temperature resistant inorganic membranes (zeolite and palladium) were developed. The zeolite membranes functioned as a high performance CO oxidation reactor, and the palladium membrane showed a very high H_2/CO selectivity.