炭微球负载钴催化剂的原位制备及其催化产氢性能研究

Carbon microsphere supported cobalt catalyst:in-situ preparation and its catalytic performance for hydrogen generation

分别以葡萄糖和硝酸钴为炭源和钴源,采用水热炭化法原位制备了炭微球负载钴金属催化剂(Co/CMS),借助扫描电镜(SEM)和X射线能谱仪(EDX)表征所制催化剂微观形貌和元素组成,利用该催化剂进行了催化硼氢化钾水解产氢实验并分析了相关催化反应的动力学过程。结果表明,所制Co/CMS催化剂球状形态完整、尺寸分布均匀,炭微球平均直径约为3.98μm,钴金属均匀负载于炭微球表面;Co/CMS催化剂对硼氢化钾水解产氢反应具有较高的催化活性,负载钴金属对催化剂的性能有显著影响,钴负载量为25%的Co/CMS催化剂催化产氢效率达到11088 mLH2·g^-1Co·h^-1;产氢速率受硼氢化钾溶液浓度影响不大,但对反应温度较敏感;钴负载量为25%的Co/CMS催化剂催化硼氢化钾溶液水解制氢反应的活化能约为33.75 kJ·mol^-1,低于Pt/C和Ru/C贵金属催化剂相应值,表明所制Co/CMS催化剂对硼氢化钾水解产氢具有较好的催化性能。

Carbon microsphere supported cobalt catalysts(Co/CMS)were in-situ prepared via hydrothermal carbonization method by using glucose and cobalt nitrate as carbon source and cobalt source,respectively.The microscopic morphology and element composition were characterized by SEM and EDX.The experiments of hydrogen generation from borohydride hydrolysis catalyzed by Co/CMS were performed and catalytic reaction kinetics was investigated.The results show that the as-prepared catalysts have spherical morphology and relatively uniform size with average diameter of approximately 3.98μm,and cobalt distributes uniformly on the surface of carbon microsphere.Co/CMS catalysts possess excellent activity for potassium borohydride hydrolysis reaction,and cobalt loading shows remarkable influence on the catalytic performance.The catalytic hydrogen production efficiency of Co/CMS with cobalt loading of 25%is determined to be 11088 mLH2·g^-1Co·h^-1 under the involved conditions.The concentration of potassium borohydride shows slight influence on hydrogen generation rate,whereas the reaction temperature exhibits significant influence.The activation energy of hydrogen generation from borohydride hydrolysis catalyzed by Co/CMS catalyst with cobalt loading of 25%is about 33.75 kJ·mol^-1,which is lower than that of Pt/C and Ru/C catalysts,indicating that the as-prepared Co/CMS catalysts exhibit excellent catalytic performance for hydrogen generation from potassium borohydride hydrolysis reaction.