Hydrogen yields from the hydrolysis of as-cast and filed powders of Al–Bi and Al–Sn alloys

The aim of this study is to evaluate hydrogen generation from Al–Bi and Al–Sn alloy powders. The powders were obtained by a filing process and were characterized by scanning electron microscopy. A combined effect of solute content and alloy microstructure was found to significantly influence hydrogen generation within sodium chloride and hydroxide media. It was observed that the Al–Bi and Al–Sn powders exhibit opposite trends in sodium chloride and sodium hydroxide solutions. A novel correlation was established between hydrogen generation, solute content, alloy microstructure, and refinement level. The microstructure defines the cathode-to-anode area ratio and the interfacial reaction between nobler and anodic regions. For fuel-cell applications in on-board and on-site automotive systems, the estimated cost of hydrogen generation ranges from 0.20 to 0.40 USD for a 400 km driving range. These findings identify the investigated alloys and the filing process as promising candidates for practical use in fuel cells. • Al–Bi and Al–Sn powders are produce using filing that is simpler than ball milling or atomization. • The cost analysis and comparison with fuel cell requirements (400 km automotive application) provides real-world context. • Microstructural analyses include cathode-to-anode area ratios (Ac/Aa) ratios and galvanic couple distances (GCD). • Hydrogen yields are associated with solute content, microstructure and with both Ac/Aa and GCD.