不同方法制备的介孔Ni/MgO催化剂上水蒸气重整苯酚制氢

利用浸渍法和水热共沉淀法两种方法,制备了介孔Ni/MgO催化剂,用于水蒸气重整生物质油模型物苯酚制取氢气;利用XRD、N2吸附/脱附、H2-TPR、TEM以及TG等手段对催化剂进行了表征。结果表明,以介孔MgO为载体,采用浸渍法制备的介孔NiO/MgO固溶体,具有较高的比表面积(60.6m2/g)以及较大的孔径(10.1nm)。与水热共沉淀法制备的催化剂相比,浸渍法制备的NiO/MgO前驱体经还原后的所得到介孔Ni/MgO催化剂Ni颗粒较小(5.0-6.0nm),分布均匀,具有较高的分散度(19.44%)。较大的比表面积能有效地促进活性金属颗粒的分散,而介孔有利于反应物和产物在催化剂孔道中的扩散。因此,该Ni/MgO催化剂在水蒸气重整苯酚制氢反应中具有较高的催化活性、稳定性和优异的抗积炭能力。

Steam reforming of phenol for producing hydrogen over nickel support on MgO prepared by different methods

MgO-supported nickel catalysts were prepared by impregnation and hydrothermal coprecipitation methods; they were characterized by XRD, N₂ sorption, H₂-TPR, TEM and TG and used in the steam reforming of biomass oil model compound-phenol for hydrogen production. The results indicated that the NiO/MgO solid solution prepared by the impregnation method displays higher surface area (60.6 m²/g) and larger pore diameter (10.1 nm), in comparison with that prepared by hydrothermal coprecipitation. After reduction, the mesoporous Ni/MgO catalyst obtained from impregnation exhibits small and uniform Ni nanoparticles (5.0-6.0 nm) with high dispersion (19.44%). As high surface area is favorable for the dispersion of Ni nanoparticles and mesoporous structure can promote the mass transfer of reactants and products, the Ni/MgO catalyst exhibits high activity as well as excellent coke resistance ability and long-term stability in the steam reforming of phenol.