含金属添加剂的负载型NiB非晶态合金催化剂的结构及催化性能

采用ICP、XRD、DSC、BET、SEM、TEM、IR对负载型Ni-M -B(M为Zn、Ag、Cu、Co、Mn、Mo、W、Fe)非晶态合金催化剂进行了表征 ,研究了这类催化剂对乙烯中微量乙炔的选择加氢性能。结果表明 ,非晶态合金以超细微粒的形式分散到载体上 ,分散度与载体有关。除Ag以多晶的形式存在外 ,其余添加金属与Ni和B形成了Ni-M -B非晶态合金。通过金属添加剂的引入 ,可以调控非晶态合金的热稳定性及催化性能。Ni54 Cu2 6 B2 0 /Al2 O3具有较高的初活性 ,积炭覆盖活性中心是催化剂失活的主要原因。

Structure and Catalytic Properties of Supported Amorphous Ni-M-B Alloy Catalysts Containing Metallic Additives

Supported amorphous Ni-M-B alloy catalysts were characterized by ICP,XRD,DSC,BET,SEM,TEM and IR.Their catalytic properties in the selective hydrogenation of acetylene in a large excess of ethene were evaluated.The results show that amorphous alloy is dispersed as ultrafine particles in the supports and the dispersion depends on the nature of the support.Ag exists as crystalline while other metallic additives form Ni-M-B amorphous alloys in the catalysts.The introduction of metallic additives can control the thermal stability and catalytic properties of the catalysts.The initial activity of Ni 54 Cu 26 B 20 /Al 2O 3 with about 4% of Ni is very high.The deactivation of Ni 54 Cu 26 B 20 /Al 2O 3 is due to the formation of polymeric materials which are produced on the acidic center and cover the active center of the catalyst.