水热法制备Ni/ Zr0.4Ce0.6O2-Al2O3催化剂上CH4-CO2重整反应研究: NiO含量的影响

采用水热合成法制备不同NiO含量的Ni/Zr0.4Ce0.6O2-Al2O3催化剂，使用X射线衍射（XPD）和H2的程序升温还原（H2-TPR）对样品进行表征，研究了NiO的含量对催化剂结构和CH4-CO2重整性能的影响。结果表征表明，少量Ni组分能在催化剂表面分散并进入CeO2-ZrO2固熔体晶格间隙而被固熔体包裹，并使固熔体晶粒变小，促进了固熔体的低温还原，而过量的NiO暴露在外生成NiO颗粒。活性测试结果表明，NiO含量少的样品活性随反应进行有较高的增长。选择适当空速，能使CH4-CO2以1：1反应。

CO2 REFORMING OF CH4 OVER Ni/Zr0.4Ce0.6O2-Al2O3 CATALYSTS PREPARED BY HYDROTHERMAL METHOD: EFFECT OF NiO CONTENT

Ni/Zr 0 4 Ce 0 6 O 2 Al 2O 3 catalyst samples with different amount of NiO were prepared by hydrothermal method and characterized by X ray diffraction and H 2 temperature programmed reduce techniques The influence of addition of NiO on structures of catalysts and activity of CO 2 reforming of methane were studied It is found that a small amount of NiO can disperse on surface and enter the crystal lattice space of solid solution and be enwrapped by CeO 2 ZrO 2 solid solution, consequently restricts the growth of CeO 2 ZrO 2 solid solution grain and promote reducibility of solid solution at low temperature, whereas excess amount of NiO exposes outside and forms crystallites of NiO A obvious increasing of activity over catalyst with lesser amount NiO is found At a certain space velocity the conversion of CH 4 and CO 2 at same molar ratio can been obtained