Formation of Mg2Ni with enhanced kinetics: Using MgH2 instead of Mg as a starting material

At a temperature over the decomposition point (375 degrees C) of MgH2, the formation of Mg2Ni is greatly enhanced from the 2MgH(2)+Ni system, as compared to the 2Mg+Ni system. In support of this finding, in-situ observation of X-ray absorption fine structure of the two systems indicates that Mg-Ni bonds form faster in the 2MgH(2)+Ni system than in the 2Mg+Ni system. Furthermore, theoretical modeling also shows that Mg atoms are readily released from MgH2 using much less energy and thus are more available to react with Ni once the dehydrogenation of MgH2 occurs, as compared to normal Mg. (C) 2012 Elsevier Inc. All rights reserved.