Cr掺杂的Co-B非晶态合金的制备及催化硼氢化钠水解制氢

采用化学还原法制备了三元非晶态Co-Cr-B纳米催化剂。采用透射电镜（TEM）、扫描电镜（SEM）、X射线衍射仪（XRD）等测试方法对催化剂的形貌、结构、成分做了表征。通过排水法进行NaBH₄溶液水解产氢反应,测量了催化剂的催化性能。结果表明,当掺杂少量的Cr时,催化剂的粒径明显减小,比表面积明显增大,催化剂的性能提高。过量的Cr会导致出现过多的氧化物和Cr ³⁺,覆盖了催化剂表面活性位点,降低催化剂的性能。当Cr与Co物质的量比为0.005时,催化剂性能最佳。与纯Co-B相比,其对硼氢化钠水解产氢速率提高了2倍。此外,研究了催化剂用量、NaBH₄浓度、反应温度、NaOH浓度等因素对NaBH₄溶液水解产氢反应的影响。

Preparation of amorphous Co-Cr-B and catalytic sodium borohydride hydrolysis for hydrogen generation

Co-Cr-B amorphous catalysts were synthesized by chemical reduction method.The morphology,structure and composition of the catalyst were characterized by scanning electron microscopy,transmission electron microscopy and X-ray diffraction.The catalytic performance of the catalyst was measured by hydrogen generation from NaBH₄ solution hydrolysis. The results showed that the particle size of the catalyst was reduced with the addition of a small amount of Cr.The specific surface area increased significantly,and the performance of the catalyst was improved.However,excessive addition of Cr caused excessive oxides and Cr ³⁺,covering the surface active sites of the catalyst,which degraded the performance of the catalyst.When the amount-of-substance ratio of Cr to Co was 0.005,the catalyst property was optimal.It showed nearly 2 times higher H₂ generation rate than that of pure Co-B catalyst.In addition,the effect of catalyst quantities,NaBH₄ concentration,reaction temperature and NaOH concentration on the hydrogen generation from NaBH₄ solution hydrolysis were also studied.