Mo、W金属氧化物对CH_4/CO_2重整Ni基催化剂性能的影响

Effects of Mo、W Metal Oxide on the Performance of Ni-based Catalysts for CO_2 Reforming of CH_4

用XRD、XPS、元素分析、TEM和活性评价等方法研究过渡金属氧化物MoO3和WO3对SiO2负载的Ni基催化剂物理化学性质和CH4/CO2重整制合成气催化性能的影响.结果表明,在负载型的镍催化剂中,MoO3和WO3的添加一方面提高了Ni的核外电子密度,减弱了对CH4深度裂解积炭;另一方面使催化剂表面镍的相对浓度降低,结构上起到了隔离、分散金属颗粒的作用,氧的相对浓度升高,有效提高了催化剂的抗烧结和抗积炭能力,显示出较好的催化稳定性.

Addition of WO3 or MoO3 to Ni/SiO2 improves the stability of the catalysts in CO2 reforming of CH4. The role of WO3 or MoO3 was studied by XRD, XPS, TEM , elementary analysis and test of catalytic performance. The results show that the addition of promoters enhances the electron density of Ni and reduces the deep decomposition of methane. Meanwhile, the surface relative content of nickel reduced and the content of oxygen increased. Lower nickel content is benefit to suppress nickel＇s sinter and higher oxygen content can remove surface carbon deposit of the catalysts, and that appear good stability of the catalyst. The results of TEM and XRD indicate that the addition of WO3 and MoO3 is benefit of isolation and dispersion of the metallic Ni.