改性铝土矿载体负载Ru催化剂上的水煤气变换制氢

采用水热法对天然铝土矿进行改性,获得高比表面积的铝土矿(bauxite)载体.用等体积浸渍法制备了Ru含量为1.0%-4.0%(质量分数,下同)的Ru/bauxite催化剂和Ru含量为2.0%的Ru/Al2O3催化剂,以水煤气变换反应为探针反应,考察了催化剂性能.利用X射线荧光元素分析(XRF)、X射线粉末衍射(XRD)、低温N2物理吸附、H2程序升温还原(H2-TPR)以及CO程序升温脱附(CO-TPD)等对载体和催化剂样品进行表征.结果表明,不同Ru含量的Ru/bauxite催化剂具有优异的水煤气变换制氢性能,优于Ru/Al2O3催化剂.其原因是铝土矿本身含有的Fe2O3与负载的Ru之间发生了相互作用,降低了Fe2O3还原温度,提高了对CO的吸附能力且降低了CO的脱附温度,进而提高了催化剂的水煤气变换反应性能.

Modified Bauxite Supported Ruthenium Catalysts for Hydrogen Evolution in the Water-Gas Shift Reaction

Hydrothermally treated bauxite with high surface area was used as a ruthenium-based catalyst support.A series of Ru/bauxite and 2.0%(mass fraction)Ru/Al 2 O 3 catalysts were prepared by incipient- wetness impregnation.The loading content of ruthenium in the Ru/bauxite catalysts was varied from 1.0% to 4.0%.The catalysts were thoroughly characterized by X-ray fluorescence(XRF),low temperature N 2 physical adsorption,X-ray diffraction(XRD),H 2 temperature-programmed reduction(H 2 -TPR),and CO temperature-programmed desorption(CO-TPD).The performances of the catalysts for the water-gas shift reaction were also investigated.The results indicated that Ru/bauxite catalysts possess an excellent ability to evolve hydrogen in the water-gas shift reaction.This was attributed to the interaction between Ru and Fe 2 O 3 in the modified bauxite,which could decrease the reduction temperature of Fe 2 O 3 ,and also improve the adsorption-desorption behavior and decrease the desorption temperature of Ru/bauxite catalysts for CO molecules,resulting in higher activity in the water-gas shift reaction.