纳米多孔镍基催化材料的结构与催化性能

用快速凝固技术制备了NiAl合金条带,经 5min球磨、在m(NaOH)∶m(H2O) =1∶4的溶液中活化处理 3h,得纳米多孔骨架镍催化剂。用XRD、SEM、AFM等对其微观组织结构进行了分析,其变化规律是:随着快淬速度的增加,合金中有效相的含量增加,晶粒变细,甚至部分非晶化;脱铝后的催化剂主要由疏松多孔的棉絮状结构和吸附在孔内的纳米级镍晶粒组成,孔径大小及分布均匀,晶粒尺寸大多在 80nm左右。将其用于呋喃加氢催化反应,在相同催化剂用量条件下,使原来在骨架镍催化下需 0 .40MPa压力才能完成的加氢反应降为 0. 25MPa即可在相同的时间内完成,反应温度还下降 2℃。

Structure and Property of Nanoscale Ni Catalysts

NiAl alloy was prepared with rapid-quenching technology.After being milled for 5 minutes and treated in NaOH solution 〔m(NaOH)∶m(H_2O)=1∶4〕 for 3 hours,the nanoscale Ni catalyst was obtained.Investigated by methods of XRD,SEM and AFM,it was found that,with increasing spun-quench speed,the efficacious phase in the alloy increases and the grains of catalysts turn smaller or partially noncrystalline.After de-aluminizing,the catalyst is mainly composed of porous batting-like structure with nano-Ni crystal grains adsorbed in the pores.The size and distribution of the pores are uniform,and diameters of fine crystal grains are about 80 nm.The catalytic performance on hydrogenation of furfuran is then tested.It is found that,compared with the process using skeleton Ni catalyst,when the hydrogen pressure is lowered from 0.40 MPa to 0.25 MPa and the reaction temperature is reduced by 2 ℃,the reaction can be accomplished in the same time.