载体对Ni基催化剂催化甲烷三重整反应性能的影响

Effect of Supports on Catalytic Performance of Ni-Based Catalysts for Tri-reforming of Methane

制备了Ni/TiO2,Ni/Mg0.5Ti0.5Ox和Ni/MgO三种催化剂并考察了它们对甲烷三重整反应的催化性能.结果表明,将Ti引入NiO-MgO体系中可以阻止固溶体的形成,而又不改变Ni的分散度.Ni/TiO2与Ni/MgO的活性随反应时间的延长而降低;Ni/Mg0.5Ti0.5Ox的催化稳定性最好,这与其氧化-还原性以及金属与载体间适度的相互作用有关.

MgO, TiO2, and Mg0.5Ti0.5Ox composite oxides were prepared by the sol-gel technique. Ni was supported on these oxides by the wet impregnation method. No peak of free NiO was observed in all X-ray diffraction patterns of the catalysts. The addition of Ti to the NiO-MgO system prevents the formation of solid solution but does not decrease the dispersion of Ni particles. The catalytic performance of the catalysts for tri-reforming of methane was investigated in a fixed-bed flow reactor at 850℃ under 1.0 MPa with space velocity of 31 800 ml/（g·h） and feed composition of n （CH4 ） ： n （CO2） ： n （H20） ： n （O2） = 1 ： 0.48 ： 0.54 ： 0.1. The catalytic activity of Ni/TiO2 and Ni/MgO decreases during the reaction period. The Ni/Mg0.5Ti0.5Ox catalyst has a relatively high stability, which is mainly dependent on the moderate interaction between the metal and the support and the moderate ability to be reduced.