An overview on activation of aluminium-water reaction for enhanced hydrogen production

Hydrogen generation from cost-effective and easily available sources is essential to commercialize proton exchange membrane ( PEM) fuel cells. The production of hydrogen from aluminium (Al) with suitable reducing agents such as water, NaBH4, and formic acid is an economically attractive technique. However, the oxide film formed on Al affects the efficiency significantly. In this review, Al activation mechanisms reported for better hydrogen production from water were discussed at length and analyzed critically. The addition of salts (NaCl/KCl, CaO, Al2O3, TiO2, AlCl3, Al(OH)(3)) and metals (Bi, Zn, Cu, Ga, In, Sn) was found to improve the Al reactivity. Al particle size reduction by ball milling in the presence of salts, addition of carbon nanotubes (CNTs), alloying with metals and amalgamation with zinc/mercury were also found to improve the reaction yield. Finally, the economic analysis of important activation methods was done and future prospects were discussed. (C) 2020 Elsevier B.V. All rights reserved.