原始合金制备方法对RaneyNi催化剂结构及加氢活性的影响

骨架镍催化剂由纳米级镍晶粒、未转变的ＮｉＡｌ３和Ｎｉ２Ａｌ３母相及其界面区组成。Ｘ射线衍射及高分辨电子显微观察发现，脱铝过程中ＮｉＡｌ３晶粒碎裂成纳米级尺寸，而Ｎｉ２Ａｌ３相则不出现碎裂现象。

EFFECT OF ALLOY PREPARATION ON MICROSTRUCTURE AND ACTIVITY OF RANEY Ni CATALYSTS

Skeletal nickel catalyst consists of nano Ni crystallites, NiAl 3 and Ni 2Al 3 phases and their boundary regions. In the beginning of leaching, NiAl 3 grains are divided into nanoscale ones, while it does not happen on Ni 2Al 3 phase. This phenomenon can be interpreted based on the structural feature of the two phases. With a similar alloy composition, the content of Ni 2Al 3 phase in the mother alloy prepared by rapid solidification is much more than that in the mother alloy prepared by normal metallurgic method. It is suggested that the increment in the hydrogenation activity for m nitrotoluene on the catalyst prepared from rapidly solidified mother alloy is attributed to the excellent leaching characteristic of Ni 2Al 3 phase.