Acta Phys. -Chim. Sin. ›› 2014, Vol. 30 ›› Issue (12): 2323-2327.doi: 10.3866/PKU.WHXB201410081

• CATALYSIS AND SURFACE SCIENCE • Previous Articles     Next Articles

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).

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