Department of Advanced Materials for Energy, Catalonia Institute for Energy Research, Jardí de les Dones de Negre 1, 2nd floor, 08930 Sant Adrià del Besós, Barcelona, Spain.
Lab Chip. 2016 Aug 7;16(15):2900-10. doi: 10.1039/c6lc00583g. Epub 2016 Jul 5.
A novel design of a silicon-based micro-reformer for onboard hydrogen generation from ethanol is presented in this work. The micro-reactor is fully fabricated with mainstream MEMS technology and consists of an active low-thermal-mass structure suspended by an insulating membrane. The suspended structure includes an embedded resistive metal heater and an array of ca. 20k vertically aligned through-silicon micro-channels per square centimetre. Each micro-channel is 500 μm in length and 50 μm in diameter allowing a unique micro-reformer configuration that presents a total surface per projected area of 16 cm(2) cm(-2) and per volume of 320 cm(2) cm(-3). The walls of the micro-channels become the active surface of the micro-reformer when coated with a homogenous thin film of Rh-Pd/CeO2 catalyst. The steam reforming of ethanol under controlled temperature conditions (using the embedded heater) and using the micro-reformer as a standalone device are evaluated. Fuel conversion rates above 94% and hydrogen selectivity values of ca. 70% were obtained when using operation conditions suitable for application in micro-solid oxide fuel cells (micro-SOFCs), i.e. 750 °C and fuel flows of 0.02 mlL min(-1) (enough to feed a one watt power source).
本工作提出了一种新颖的基于硅的微重整器设计，用于在车载条件下从乙醇中制取氢气。该微重整器完全采用主流的微机电系统技术制造，由通过绝缘膜悬挂的低热质量的活性结构组成。悬挂结构包括嵌入式电阻式金属加热器和大约每平方厘米 20k 个垂直排列的贯穿硅微通道阵列。每个微通道长 500μm，直径 50μm，允许采用独特的微重整器配置，其每投影面积的总表面积为 16cm(2)cm(-2)，每体积的总表面积为 320cm(2)cm(-3)。当微通道的壁用 Rh-Pd/CeO2 催化剂的均匀薄膜涂覆时，它们就变成了微重整器的活性表面。在受控温度条件（使用嵌入式加热器）下进行乙醇的蒸汽重整，并将微重整器作为独立设备进行评估。当使用适合于微固体氧化物燃料电池（μ-SOFC）应用的操作条件（即 750°C 和燃料流速为 0.02mlL min(-1)（足以供应一个 1 瓦特的电源））时，获得了高于 94%的燃料转化率和大约 70%的氢气选择性值。
