Ni含量对Co_(1-x)Ni_xB催化水解放氢性能的影响(英文)

采用化学还原法以乙醇为溶剂在冰水浴中合成了一系列Co1-xNixB合金催化剂,研究了该系列合金不同Ni含量对NaBH4水解放氢性能的影响.X射线衍射(XRD),扫描电镜(SEM)和透射电镜(TEM)显示Co1-xNixB合金是纳米非晶态颗粒.放氢测试表明Co1-xNixB具有很高的催化活性.放氢速率先随着Ni含量的增加而增大,并在x=0.15时放氢速率达到最大值,然后随x值的增加而减小.298K时Co0.85Ni0.15B合金催化碱性硼氢化钠水解的最大放氢速率可达4228mL·min-1·g-1,CoB和Co0.85Ni0.15B合金催化放氢的活化能分别为34.25和31.87kJ·mol-1.因此以乙醇为溶剂合成的Co1-xNixB合金具有较高的催化活性.

Effect of Ni Content in Co1-xNixB Catalysts on Hydrogen Generation during Hydrolysis

A series of Co1-xNixB alloy catalysts were synthesized in ethanol by chemical reduction in an ice-water bath. The catalytic hydrolysis of an alkaline NaBH4, solution was studied by changing the Ni content in the Co1-xNixB catalyst. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy revealed that the asprepared Co1-xNixB alloys were ultrafine nanoparticles in amorphous form. Hydrogen generation measurements showed that the as-prepared Co1-xNixB alloys exhibited excellent catalytic activity. The hydrogen generation rate firstly increased as the Ni content increased in the Co1-xNixB catalyst, and it reached the highest at x=0.15, then decreased as x increased. The highest hydrogen generation rate at 298 K was 4228 mL·min-1·g-1 for Co0.85Ni0.15B during the catalytic hydrolysis of the alkaline sodium borohydride solution. The activation energies of the Co0.85Ni0.15B alloy and CoB were 31.87 and 34.25 kJ·mol-1, respectively. This showed that the Co1-xNixB alloys synthesized in ethanol had high activity.