Abstract
MgH2 particles were synthesized by wet impregnation within the pores of the mesoporous materials SBA15 and CMK3. XRD and TEM results of Mg/SBA15 compounds revealed MgO surface impurities, indicating non-compatibility of SBA15 for the synthesis of MgH2 particles within SBA15 pores. No impurity phase was detected in Mg/CMK3 compounds. Thermal desorption behavior of MgH2/CMK3 compounds were studied by varying the MgH2 loading amount in CMK3. TPD results of MgH2/CMK3 compounds demonstrated that the onset and maximum hydrogen desorption temperatures were significantly influenced by the MgH2 loading amount. MgH2/CMK3 compounds with 20 wt% loading released hydrogen at a temperature of 253 degrees C. Its corresponding decomposition enthalpy was equal to 52.38+/-2.16 kJ/mol H-2. Furthermore, TEM images of this sample demonstrated the existence of well-dispersed MgH2 nanocrystallites (d similar to 4 nm) inside the pores of CMK3 template. (C) 2012 Elsevier Ltd. All rights reserved.