担载非晶态Ni-B合金催化材料化学镀法制备

Preparation of theγ-A1_2O_3 Supported Amorphous Ni-B Alloy Catalysts by Electroless Plating

以NH3为稳定剂,KBH4为还原剂,考察了化学镀法制备γ-Al2O3担载Ni-B非晶态合金催化剂工艺条件。NH3浓度和温度对镀液的稳定性有显著影响,加料顺序亦影响催化剂制备的顺利进行。14℃下,NH3浓度13．5％,镀液稳定时间8 h,当NH3浓度降到5．4％时,稳定剂完全失去作用。当温度升到30℃,NH3浓度13．5％,镀液稳定时间降到3．5 h。在γ-Al2O3表面预载微量金属镍敏化载体表面,可以催化化学镀的顺利进行。XRD数据显示化学镀法制备Ni-B合金的非晶态特性明显优于普通化学还原法。

The conditions that the catalysts of amorphous alloy Ni-B supported on γ-Al2O3 were prepared by electroless plating induced by Ni（0） pre-tacked on supporter were studied. Ni（0） pre-impregnated on γ-Al2O3 could catalyze KBH4, reduced electroless nickel deposits avoiding to use Pd etc. inducer and leading to the motley atom doping. The concentration of NH3 as stabilizing agent and temperature affected stability of the plating solution obviously. The plating solution containing NH3 13.5% was kept steady for 8 h at 14℃, while containing NH3 5.4% the solution reacted immediately at the same temperature, and the plating solution with same concentration of NH3 （13.5%） was kept steady for 3.5 h only when the temperature rose to 30℃. Ni（ Ⅱ ） species on the surface derive from pre-immersed γ-Al2O3 with solution containing [Ni（NH3）6]^2＋ was not reduced by KBH4. This could be attributed to strong interaction between [Ni（NH3）6]^2＋ and surface oxygen of alumina. XRD date indicate that the amorphism of catalytic materials prepared by electroless plating were more notable than that prepared by common chemical reduction.