Effect of low B addition on Al-Zn alloy's hydrogen production performance

Abstract

Aluminium hydrolysis is a promising method for hydrogen generation due to its instant hydrogen production, simplicity, controllability, and safety properties. Moreover, Al is very common, recyclable, lightweight material and it has no degradation problem to supply hydrogen in energy conversion devices. Hydrogen produced by Al can be easily adapted to fuel cells to convert energy into higher efficiency. In this study, the effect of low B additions (0.1, 0.3, and 0.5 wt.%) to the Al-2wt.%Zn alloy's hydrogen generation performance is investigated. Different temperatures (25, 50, and 80 °C) and different concentrations of NaOH (1, 3, and 5 M) are studied to observe their effects on the hydrogen production and corrosion rate. At 80 °C and 5 M NaOH concentration, in Al-2wt.%Zn-0.5wt.%B alloy, around 83% higher hydrogen generation performance is obtained than Al-2wt.% Zn alloy. The hydrolysis reaction kinetics are investigated with the Arrhenius equation and by low B addition, activation energy of the Al-2wt.%Zn and Al-2wt.%Zn-0.5 wt.%B alloys are decreased from 26.717 kJ mol−1 to 23.526 kJ mol−1.