NiCl_2溶液中氢化燃烧合成MgH_2水解制氢性能研究

Study of hydrogen generation via hydrolysis of HCS Mg-based hydride in NiCl_2 solution

随着氢燃料电池的快速发展,越来越多的研究学者们开始关注移动氢源技术并提出了在线制氢的概念。采用氢化燃烧合成法(Hydriding Combustion Synthesis,HCS)制备的镁基氢化物与H2O、MgCl2和NiCl_2溶液水解制取氢气。深入研究了在NiCl_2溶液中制氢性能,主要研究了NiCl_2溶液浓度、NiCl_2溶液体积和反应温度对制氢性能的影响。实验结果表明NiCl_2浓度的增加有利于降低体系pH值,从而改善水解制氢性能。J-M-A方程拟合证明了HCS MgH_2在303、313和323 K温度下水解符合成核与长大机制,为一维扩散过程。水解性能测试表明,0.1 g MgH_2与10 mL 0.5 mol/L NiCl_2溶液进行反应时,当温度为323 K时,60 min内制氢量达到1 628 mL/g,制氢转化率高达95.8%。

With the rapid development of hydrogen fuel cells,more and more researchers have focused on mobile hydrogen technology and put forward the concept of on-line hydrogen generation.Mg-based hydride prepared by hydriding combustion synthesis(HCS)was used to generate hydrogen via hydrolysis in H2O,MgCl2 and NiCl2 solutions.The hydrogen generation performance via the hydrolysis of Mg-based hydride in NiCl2 solution was intensively studied.The effects of NiCl2 solution concentration,NiCl2 solution volume and the reaction temperature on hydrogen generation performance were further studied.The experimental results show that the hydrogen generation performance was enhanced with increasing the concentration of NiCl2 solutions,due to the pH decrease.J-M-A equation fitting proved that the hydrolysis reactions of HCS MgH2 in different reaction temperatures(303,313 and 323 K)obeyed the nucleation growth mechanism and belonged to one dimensional diffusion process.Hydrolysis performance test shows that 1 628 mL/g hydrogen generation and 95.8%conversion can be obtained via the hydrolysis of 0.1 g MgH2 in 10 mL NiCl2(0.5 mol/L)at 323 K.