ANALYSIS OF DOPED RODLIKE SURFACE FIBERS IN AL-AL3NI EUTECTIC ALLOYS

Undoped and Cr doped rodlike Al-Al3Ni eutectics have been studied as initial alloys of Raney nickel catalysts. The aim was to localize the dopant at different stages of the catalyst life: in the initial alloy, after Al leaching out, and after hydrogenation reaction. We have followed this dopant by STEM analysis and high resolution Auger spectroscopy. The outcome is that during Al leaching out, the dopant is also extracted from its initial phase and then forms a deposit on the Ni crystallites of the catalyst. Moreover, during the hydrogenation, the quantity of Cr remains roughly constant.