Role of Ball Milling of Aluminum Powders in Promotion of Aluminum-Water Reaction to Generate Hydrogen

Abstract

Effect of ball milling (BM) of an aluminum powder on hydrogen generation through a reaction with hot water was investigated. BM increased surface area of the aluminum particles, increased crystalline imperfections in the aluminum lattice, and removed a native oxide film on surface of the particles. The increase in surface area of the particles was studied by measurement of particle size and examination of cross section of the particles. The effect of crystalline imperfections was studied by room temperature recovery and high temperature annealing of the ball-milled particles. The effect of the native oxide film and its thickness was studied by exposing ball-milled aluminum particles to air for different durations. Hydrogen production capability of different aluminum powders after each of the above mentioned treatments was tested and correlated to microstructural changes.