Role of Modification Agent Coverage in Hydrogen Generation by the Reaction of Al with Water

Abstract

Previous works indicated that Al particle surfaces could be modified by fine γ‐Al2O3 grains, which can be used as a hydrogen‐generation material, where the fine γ‐Al2O3 grains were produced by the decomposition of the Al(OH)3 phase in the mixture. In this work, commercially available γ‐Al2O3 powder was directly used as the modification agent and mixed with Al powder and heat treated at an elevated temperature. It was found that the modified Al powder produced by directly using γ‐Al2O3 has an obvious shorter time for complete hydrogen generation than that using Al(OH)3‐produced γ‐Al2O3. Microstructure analyses revealed that directly using γ‐Al2O3 powder has a better coverage of fine γ‐Al2O3 grains on Al particle surfaces than the Al(OH)3‐produced γ‐Al2O3. This implies that a uniform distribution of modification agents on Al particle surfaces is an important factor for the Al–water reaction dynamics.