第四周期过渡金属催化硼氢化钠分解制氢研究

Fourth period transition metals for hydrogen generation from catalytic hydrolysis of sodium borohydride solution

考察了MnSO_4、FeSO_4、CoCl_2、NiCl_2和CuCl等盐原位还原催化硼氢化钠的水解制氢性能,实验确定催化硼氢化钠水解制氢活性高低顺序:CoCl>NiCl>FeSO_4>CuCl_2>MnSO_4,并发现这与第四周期过渡金属d轨道上的电子数有密切关系。硼氢化钠分解产氢速率与FeSO_4、CoCl_2和NiCl_2用量成正比,说明催化硼氢化钠水解产氢的活性中心为过渡金属,且硼氢化钠水解产氢反应对盐的用量为一级反应。实验计算出FeSO_4、CoCl_2和NiCl_2催化硼氢化钠分解制氢反应的活化能分别为52.01、46.33、58.70 kJ/mol,发现硼氢化钠产氢速率与活化能之间没有必然联系。

The performances of fourth period transition metals from in situ reduction of their salts （MnSOa,FeSO4,CoCl2, NiCl2, and CuCl2 etc. ） for hydrogen generation from catalytic hydrolysis of sodium borohydride solution were investigated.Results showed that the order of their activity for catalytic hydrolysis of sodium borohydride solution to hydrogen was COCl2〉 NiCl2〉FeSOa〉CuCl2〉MnSO4.This was closely related to the electron number of d orbits of the transition metals for those slats. The rate of hydrogen generation from catalytic hydrolysis of sodium borohydride solution was proportional to the amount of FeSO4, CoCl2, and NiCl2 used.h suggested that the active sites for hydrogen generation from catalytic hydrolysis of sodium borohydride solution were the transition metals respectively.Moreover, the reaction of hydrogen generation from catalytic hy drolysis of sodium borohydride solution for the amount of those salts was first-order reaction.The activation energy of hydrogen generation from catalytic hydrolysis of sodium borohydride solution using FeSO4,CoCl2,and NiCl2 were 52.01 kJ/mol, 46.33 kJ/mol, and 58.70 kJ/mol, respectively.This indicated that there was no direct correlation between the rate of hydrogen generation from catalytic hydrolysis of sodium borohydride solution and the activation energy.