The effect of chromium (III) oxide (Cr2O3) nanopowder on the microstructure and cyclic hydrogen storage behavior of magnesium hydride (MgH2)
M. Polanski , J. Bystrzycki , R.A. Varin , Tomasz Płociński , Marcin Pisarek
AbstractHigh energy ball milling in a Fritsch P6 planetary ball mill was used for the synthesis of the nanocomposite of MgH2 with 10 wt.% of Cr 2O3 nanopowder catalyst (particle size <50 nm). After ball milling for 1 h the resulting grain size of β-MgH2 was equal to ∼30 nm. Subsequently, the nanocomposite was subjected to 150 desorption/absorption cycles at 325 °C. A gradual loss of hydrogen storage capacity upon cycling from ∼5.2 wt.% after 1 cycle to ∼4.6 wt.% after 150 cycles is observed on respective PCT curves obtained at 325 °C after every 25 cycles. The TPD curves temperature maxima are gradually shifted to a higher temperature range with increasing number of cycles which may indicate a lowering of the overall rate of transformation. Thorough microstructural investigations using such techniques as X-ray diffraction (XRD), scanning transmission electron microscopy (STEM) and X-ray photoelectron spectroscopy (XPS) of the samples after 150 cycles of desorption/absorption show profound microstructural changes such as sintering of individual powder particles into agglomerates, increase in grain/crystallite size (>100 nm), segregation of the Cr2O3 particles to the interfaces between the sintered Mg particles and some reduction of Cr2O3 to Cr and MgO. All these microstructural changes seem to be responsible for the reduction of hydrogen storage capacity upon cycling and lowering the overall rate of transformation. © 2010 Elsevier B.V. All rights reserved.
|Journal series||Journal of Alloys and Compounds, ISSN 0925-8388, (A 35 pkt)|
|Pages||2386 - 2391|
|Publication size in sheets||0.5|
|Keywords in English||Ball milling; Chromium oxide (Cr2O3); Cycling; Magnesium hydride (MgH 2); Microstructure; Solid state hydrogen storage|
|ASJC Classification||; ; ;|
|Publication indicators||= 22; = 24; : 2011 = 1.457; : 2011 = 2.289 (2) - 2011=2.104 (5)|
|Citation count*||28 (2019-12-28)|
* presented citation count is obtained through Internet information analysis and it is close to the number calculated by the Publish or Perish system.