非晶态合金Ni~6~3Zr~3~7催化剂的活化处理及表面状态

酸洗加负压加热预处理可以明显地改善非晶态Ni~6~3Zr~3~7合金条带的乙炔加氢反应催化活性, 采用俄歇电子能谱(AES), X射线光电子能谱(XPS), 并结合氩离子溅射对预处理前后合金的表层成分深度分布及化学状态进行了研究。采用XRD及BET方法对预处理前后条带的结构及比表面积进行了测定。结果表明, 由于Zr的选择氧化, 非晶条带原始表面被一层锆的氧化物覆盖。预处理后, 条带比表面积从0.05m^2/g增加到了15.41m^2/g, 条带表面Ni与Zr原子比从预处理前的Ni~<~1Zr~>9~9增加到了Ni~5~7Zr~4~3, 随合金浓度变化, 金属Ni的Ni2p~3~/~2结合能发生变化, 并且随Zr浓度降低, Ni2p~3~/~2结合能降低。

Activating pretreatment and surface characteristics of amorphous alloy Ni~6~3Zr~3~7 catalyst

The amorphous Ni63Zr37 alloy ribbon surface exhibited high catalytic activity for hydrogenation of ethyne to ethylene when the alloy ribbon surface was pretreated with a dilute acid solution and heated under neg. atomsphere pressure successively. The elemental composition and chem. characteristics as a function of depth below the surface was determine by means of Auger electron spectroscopy and XPS combined with the use of argon ion bombardment. The ribbon structure and surface area were estimated by XRD and the BET method. The raw amorphous alloy surface was covered by a thin layer of oxides of Zr. After pretreatment, the surface area was changed from 0.05 to 15.41 m2/g, elemental Ni to Zr ratio on the ribbon surface was changed from Ni?Zr?9 to Ni57Zr43. The decrease of surface Zr concentration reduces the Ni 2p3/2 binding energy of surface Ni.