Catalytic activity of titania polymorphs towards desorption reaction of MgH2

Hydrogen desorption properties of MgH2 ball milled with two different TiO2 polymorphs, rutile and anatase, were studied. Structural characterization has been done by X-ray diffraction (XRD) analysis, particle size analysis (PSD) and scanning electron microscopy (SEM). The mechanism of desorption and...

Full description

Saved in:
Bibliographic Details
Published in:International journal of hydrogen energy 2016-03, Vol.41 (8), p.4703-4711
Main Authors: Vujasin, Radojka, Mraković, Ana, Kurko, Sandra, Novaković, Nikola, Matović, Ljiljana, Novaković, Jasmina Grbović, Milošević, Sanja
Format: Article
Language:English
Subjects:
Catalytic properties
Composites
Hydrogen storage
MgH2
TiO2 polymorphs
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Hydrogen desorption properties of MgH2 ball milled with two different TiO2 polymorphs, rutile and anatase, were studied. Structural characterization has been done by X-ray diffraction (XRD) analysis, particle size analysis (PSD) and scanning electron microscopy (SEM). The mechanism of desorption and the apparent activation energy for desorption were investigated by applying isoconversional kinetic analysis of DTA spectra, while desorbed species were followed by TPD coupled with mass spectroscopy. It has been demonstrate that the addition of rutile TiO2 significantly decrease the apparent activation energy for desorption (Edesa), while addition of anatase titania has negligible influence on Edesa. Such behaviour could be explained in terms of the same crystal structure of rutile TiO2 and MgH2. Further, the mechanism of desorption changes from Avrami–Erofeev n = 3 for pure MgH2 to Avrami–Erofeev n = 4 for composite materials. •Effect of different TiO2 phases on H desorption from MgH2–TiO2 composite is studied.•Addition of rutile notably reduce the apparent activation energy for desorption.•Such behaviour is due to the same crystal structure of rutile TiO2 and MgH2.
ISSN:0360-3199
1879-3487
DOI:10.1016/j.ijhydene.2016.01.095