Nd，Ce和La改性对Ni/SBA-15催化剂在CH4/CO2重整反应中性能的影响

Effects of Nd, Ce, and La modification on catalytic performance of Ni/SBA-15 catalyst in CO_2 reforming of CH_4

以稀土金属Nd,Ce或La的氧化物为助剂,采用β-环糊精浸渍法对Ni/SBA-15催化剂进行了改性,并运用X射线衍射、N2吸附-脱附、程序升温还原和热重等手段考察了改性的催化剂在CO2重整CH4制合成气反应中的催化性能.结果表明,Nd等稀土金属氧化物的添加对催化剂孔结构和晶相结构等性质影响不大,但可影响NiO的还原;Nd的添加使NiO与载体之间以Ni-Nd-O形式相互作用,促进了活性组分NiO的还原.其中,Nd的添加量为5–10 wt%时所制备的催化剂在重整反应中的催化活性最高,且具有很强的抗积碳性能.La和Ce氧化物促进的Ni催化剂也表现出类似的性质和催化性能.

Rare-earth metal （Nd, Ce, and La） oxides modified Ni/SBA-15 catalysts were prepared by aβ-cyclodextrin-modified impregnation method. The physicochemical properties of the catalysts were characterized using X-ray diffraction, N2 adsorption-desorption, temperature-programmed reduction, and thermogravimetric analysis. The catalytic performance of the catalysts was evaluat-ed in the CO2 reforming of CH4 to syngas. The characterization results showed that Nd, Ce, and La modification had little effect on the textural structures and crystalline phases of the obtained cata-lysts but influenced the reduction of NiO species. Addition of Nd favored interactions between Ni and SiO2, possibly as a result of the formation of Ni-Nd-O species. The results for the CO2 reforming of CH4 revealed that the addition of suitable amounts of Nd （5-10 wt%） improved the catalytic ac-tivity and stability. A small amount of carbon was deposited over the used Nd-modified catalysts. The properties of Ni/SBA-15 catalysts modified with La and Ce were similar to those of the Nd-modified catalysts.