Reaction kinetic behaviour with relation to crystallite/grain size dependency in the Mg-Si-H system

摘要: Abstract An empirical understanding of the relationship between crystallite size and reaction kinetics for dehydrogenation MgH 2 in presence Si was determined. combined with under different conditions to obtain varying sizes both reactants. Thermal analysis isothermal desorption were undertaken kinetic information therefore determine activation energies as well rate limiting step each sizes. It found that there is a strong correlation energy growth Mg phase, however, any nucleation (of Si) less evident. Direct measurements behaviour from manometric Sieverts apparatus showed initial fastest when mixed nanoparticles, this sample not able fully desorb. Data then used well-known theoretical models reaction. The three dimensional Carter–Valensi (or contracting volume) diffusion model could be describe most reactions. These results have led proposed mechanism formation during decomposition