活化非晶Fe_(80)Zr_(12)B_8合金的表面状态与催化活性

SURFACE STATE AND CATALYTIC ACTIVITY OF ACTIVATED AMORPHOUS Fe_(80)Zr_(12)B_8 ALLOY

采用Auger电子能谱(AES),X射线光电子能谱(XPS)及扫描Auger探针(SAM)等分析手段,并结合氩离子轰击剥层对非晶Fe_(80)Zr_(12)B_8合金条带的表层成分分布、元素化学状态及表面形貌进行了研究。实验结果表明:原始条带的贴辊侧和自由侧表面均为一层铁的氧化物覆盖。经活化后,条带两侧表面均发生了组元B的显著富集和氧化,出现了α-Fe微细晶粒,近表层发生了B和Zr的选择氧化,形成了多孔的表面结构,比表面积从原始条带的0.11m^2/g增加到了2.68m^2/g。

The depth profile of composition, chemical state of elements and morphology of as-received and activated amorphous Fe_(80)Zr_(12)B_8 alloy ribbons have been studied by means of Auger electron spectroscopy, X-ray photoelectron spectroscopy and scanning Auger microprobe combined with Ar ion bombardment. Both dull and free sides of the as-received ribbons were covered with an iron oxide layer. While a pronounced surface segregation and oxidation of B were observed on both sides of activated ribbons, the fine microcrystalline α-Fe was precipitated as well as B and Zr were oxidized selectively in subsurface layer. On both sides of ribbons, a porous surface structure was formed. The BET surface area was measured to be increasing from 0.11 to 2.68 m^2/g. The principal mechanism of in situ activation has been discussed.