%0 journal article
%@ 0925-8388
%A Barkhordarian, G.,Klassen, T.,Bormann, R.

%D 2006
%J Journal of Alloys and Compounds
%N 1-2
%P 249-255 
%R doi:10.1016/j.jallcom.2005.05.037
%T Kinetic investigation of the effect of milling time on the hydrogen sorption reaction of magnesium catalyzed with different Nb2O5 contents
%U https://doi.org/10.1016/j.jallcom.2005.05.037
1-2 
%X The effect of milling time and Nb2O5 content on the magnesium hydrogen sorption reaction is investigated in this paper. The absorption and desorption kinetics of magnesium at 300 ◦C, with 0.05, 0.1, 0.2, 0.5, 1 mol% Nb2O5 contents and after 2, 5, 10, 20, 50, 100 h milling were measured. Reaction kinetics can be enhanced up to a certain limit by increasing the milling time or increasing the Nb2O5 content. The kinetic rate constants for different milling times and Nb2O5 contents were calculated and compared. Furthermore the rate-limiting step of the absorption and the desorption reactions was determined by fitting the respective kinetic equations. While the absorption is diffusion controlled,,the rate-limiting step for desorption changes, with increasing of milling time or Nb2O5 content, from chemisorption to interface velocity of the transformed phase, demonstrating the effectiveness of the Nb2O5 catalyst.