Wall-loaded Pt/TiO2/Ti Catalyst and Its Application in Ammonia Oxidation Reaction in Microchannel Reactor
Wall-loaded Pt/TiO2/Ti Catalyst and Its Application in Ammonia Oxidation Reaction in Microchannel Reactor
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DOI：
10.1039/c6ra03993f
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发表时间：
2016-03
期刊：
影响因子：
3.9
通讯作者：
Wei Jiang;Jiaping Qiu;Wei Qiu;S. Yuan;Houfang Lu;Bin Liang
中科院分区：
文献类型：
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作者：
Wei Jiang;Jiaping Qiu;Wei Qiu;S. Yuan;Houfang Lu;Bin Liang
微通道反应器是一种具有工业应用前景的反应器类型。然而，在微通道中负载多相催化剂是麻烦的，因为高的压降和严重的流体流动磨损。本研究以Pt/TiO 2/Ti催化剂为微通道壁，设计了一种自制的微通道反应器。这种壁载Pt/TiO 2/Ti催化剂是通过阳极氧化Ti箔并在阳极表面层上光沉积Pt来制备的。然后将箔组装为微通道的侧壁。以氨氧化反应为探针反应，考察了壁载催化剂对微通道反应器性能的影响。模拟和实验结果表明，在以下条件下可以获得100%的氨转化率：温度，300 °C;气体时空速，35 000 h-1;催化剂负载百分比，总通道面积的85%;氨与氧的体积比，1：1。13，在不存在氮气的情况下，具有长80 mm、宽1.0 mm和高0.3 mm的微通道。微通道中的压降小至1.18 kPa，并且温度分布相对均匀。值得注意的是，NOx选择性显著提高，在300 °C下变为88.32%。模拟结果证实，选择性表现出这样高的改善，由于NOx的停留时间短，因为独特的盲孔结构的TiO 2纳米管和由此产生的大的传质阻力。使用壁载Pt/TiO 2/Ti催化剂的该反应器即使在运行360 h后也运行稳定，没有任何显着的性能衰减。因此，在阳极金属上负载催化剂的微通道反应器是一个具有吸引力的前景的大规模应用的快速气-固放热反应。
A microchannel reactor is a promising reactor type for industrial applications. However, loading heterogeneous catalysts in the microchannels is troublesome because of the high pressure drop and serious fluid flow abrasion. In this research, a home-made microchannel reactor was designed by using a wall-loaded Pt/TiO2/Ti catalyst as the microchannel wall. This wall-loaded Pt/TiO2/Ti catalyst was prepared by anodizing a Ti foil and photodepositing Pt on the anodic surface layer. The foil was then assembled as a side wall of the microchannel. Ammonia oxidation was used as the probe reaction for evaluating the performance of this microchannel reactor by using the wall-loaded catalyst. Simulation and experimental results show that 100% ammonia conversion can be obtained under the following conditions: temperature, 300 °C; gaseous hourly space velocity, 35 000 h−1; catalyst loading percentage, 85% of the total channel area; and ammonia to oxygen volume ratio, 1 : 13, in the absence of nitrogen, with a microchannel of length 80 mm, width 1.0 mm, and height 0.3 mm. Pressure drop in the microchannel is as small as 1.18 kPa, and temperature distribution is relatively uniform. Notably, NOx selectivity is significantly improved to become 88.32% at 300 °C. Simulations confirm that the selectivity showed such a high improvement owing to the short residence time of NOx because of the unique blind-hole structure of TiO2 nanotubes and the resulting large mass transfer resistance. The operation of this reactor with the wall-loaded Pt/TiO2/Ti catalyst is stable without any remarkable performance decay even after 360 h of operation. Hence, the microchannel reactor with a wall-loaded catalyst on the anodic metal is an attractive prospect for large-scale applications of rapid gas-to-solid exothermic reactions.