物理化学学报 >> 2014, Vol. 30 >> Issue (12): 2323-2327.doi: 10.3866/PKU.WHXB201410081

催化和表面科学 上一篇    下一篇

MgH2+20%(w)MgTiO3复合材料的吸/放氢性能

王家盛1, 韩树民1,2, 李媛1, 沈娜1, 张伟1   

  1. 1. 燕山大学环境与化学工程学院, 河北省应用化学重点实验室, 河北 秦皇岛 066004;
    2. 燕山大学亚稳材料科学与技术国家重点实验室, 河北 秦皇岛 066004
  • 收稿日期:2014-07-14 修回日期:2014-10-08 发布日期:2014-11-27
  • 通讯作者: 韩树民 E-mail:hanshm@ysu.edu.cn
  • 基金资助:

    国家自然科学基金(50971112, 51001043)及河北省高等学校科学技术研究重点项目(ZD2014004)资助

Hydriding/Dehydriding Properties of an MgH2+20%(w) MgTiO3 Composite

WANG Jia-Sheng1, HAN Shu-Min1,2, LI Yuan1, SHEN Na1, ZHANG Wei1   

  1. 1. Hebei Key Laboratory of Applied Chemistry, College of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao 066004, Hebei Province, P. R. China;
    2. State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, Hebei Province, P. R. China
  • Received:2014-07-14 Revised:2014-10-08 Published:2014-11-27
  • Contact: HAN Shu-Min E-mail:hanshm@ysu.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (50971112, 51001043) and Scientific Research Projects in Colleges and Universities in Hebei Province, China (ZD2014004).

摘要:

为了降低MgH2的吸放氢温度, 提高其吸放氢动力学性能, 本文通过球磨方法制备了MgH2+20%(w)MgTiO3复合储氢材料, 并研究了其储氢性能. X射线衍射(XRD)结果表明, MgTiO3在与MgH2球磨过程中生成Mg2TiO4和TiO2, 并且Mg2TiO4和TiO2在体系的吸放氢过程中保持稳定, 能够对MgH2的吸放氢过程产生催化作用. 程序升温脱附和吸/放氢动力学测试结果表明, 添加MgTiO3后MgH2的初始放氢温度从389 ℃降至249 ℃.150 ℃下的吸氢量从0.977%(w)提高到2.902%(w), 350 ℃下的放氢量从2.319%(w)提高到3.653%(w). 同时, MgH2放氢反应的活化能从116 kJ·mol-1降至95.7 kJ·mol-1. 与MgH2相比, MgH2+20%(w) MgTiO3复合材料的热力学与动力学性能均有显著提高, 这主要是由于球磨和放氢过程中原位生成的TiO2和Mg2TiO4具有良好的催化活性.

关键词: 储氢性能, MgH2, MgTiO3, 催化活性, 活化能

Abstract:

With the aim of decreasing the dehydriding temperature and improving the hydriding/dehydriding kinetic properties of MgH2, we prepared MgH2+20%(w) MgTiO3 composite via ball-milling, and investigated the hydrogen storage properties of the composite. X- ray diffraction (XRD) results showed that the MgTiO3 decomposed into Mg2TiO4 and TiO2 during the ball-milling. These two resulting compounds remained stable during the hydriding/dehydriding processes, working as catalysts for the hydriding/dehydriding. Temperatureprogrammed- desorption (TPD) and hydriding/dehydriding kinetics tests showed that doping MgH2 with MgTiO3 lowered the onset dehydrogenation temperature of MgH2 from 389 to 249 ℃, as well as increasing the hydrogen absorption amount from 0.977%(w) to 2.902%(w) at 150 ℃, and increasing the desorption amount from 2.319% (w) to 3.653%(w) at 350 ℃. The MgTiO3 additive decreased the dehydriding activation energy of MgH2 from 116 to 95.7 kJ·mol-1. The thermodynamic and kinetic performance of the MgH2+20%(w) MgTiO3 composite was significantly improved compared with pristine MgH2, which was attributed to the high catalytic activity of the (insitu formed) TiO2 and Mg2TiO4 during the ball-milling and dehydriding processes.

Key words: Hydrogen storage property, MgH2, MgTiO3, Catalytic activity, Activation energy

MSC2000: 

  • O643.32