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采用TEM和HREM方法观察到由激冷合金制备的Raney-Ni催化剂中两种尺寸的孔结构,初始Ni_2Al_3晶界处形成的尺寸为2～5 nm的间隙孔和Ni_2Al_3晶粒内部形成的尺寸约为2 nm的微孔.制备合金的激冷方法导致Ni_2Al_3初始晶粒细化,在最佳脱铝条件下获得两种尺寸的孔结构的最佳配合,这可能是获得该催化剂对邻硝基甲苯加氢高催化活性的一个重要原因.提出了研制高性能Raney类型催化剂的一种可能思路,即对于特定的催化反应,选择适当的合金制备方法获得需要的初始合金组织,在最佳脱铝条件下获得对于该反应合适的孔结构,得到高的活性比表面积,从而获得优良的催化活性和选择性.
The TEM and HREM methods were used to observe the pore structure of two sizes of Raney-Ni catalysts prepared from chilled alloy. The size of interstitial pores with size of 2 ~ 5 nm formed at the initial Ni_2Al_3 grain boundaries and the size of Ni_2Al_3 grains 2 nm micropores.The preparation of alloy quenching method led to the initial grain refinement of Ni_2Al_3, the optimum dealumination conditions to obtain the best fit of the pore structure of two sizes, which may be the catalyst for o-nitro An important reason for the high catalytic activity of toluene hydrogenation.A possible idea to develop a high performance Raney type catalyst is to select the proper alloy preparation method for the specific catalytic reaction to obtain the desired initial alloy structure, Under the conditions to obtain a suitable pore structure for the reaction, to obtain a high specific surface area, so as to obtain excellent catalytic activity and selectivity.