Bulk nanoporous aluminum enables on-demand hydrogen generation from water and supports additional combustion and energy-related applications.

Hydrogen is not yet widely used as a sustainable energy carrier because common production methods are not carbon-free. Hydrogen storage is challenging because hydrogen gas has very low volumetric energy density. On-board storage commonly relies on compressed tanks. Pressurized flammable gas cylinders create safety concerns and drive the need for on-demand, on-site hydrogen generation.

The invention provides bulk nanoporous materials, including bulk nanoporous aluminum, that generate hydrogen when contacted with water. These materials are fabricated through an air-free non-aqueous electrolytic dealloying process that selectively removes sacrificial material from a parent alloy. The same process can recover the sacrificial material for reuse. The disclosed nanoporous aluminum supports hydrogen generation without added catalysts or reaction promoters in the aluminum-water system.

A parent mixture such as an aluminum-magnesium alloy is contacted with an electrolyte and electrodes, and voltage or current is applied to selectively remove the sacrificial component. This process leaves behind a nanoporous structure with interconnected ligaments and open pores. The disclosed materials can include hierarchical pore and ligament structures, with mesoscopic ligaments reported in the 10-20 nm range. This hierarchical porosity facilitates water transport into the bulk material and hydrogen transport out during reaction.

• Enables on-demand hydrogen generation from water using bulk nanoporous aluminum
• Uses an electrolytic dealloying process that can recover sacrificial material for reuse
• Supports additional uses including heat generation, combustion support, and integrated power systems

• On-board hydrogen generation: Bulk nanoporous aluminum can generate hydrogen from water for disclosed on-board hydrogen production systems.
• Fuel cell vehicles: The patents describe vehicles that use hydrogen evolved from water contact with the composition to generate electricity in a fuel cell
• Generator units: The disclosed generator units combine the composition, water supply, and fuel cell to provide electricity through an outlet
• Solid propellant combustion: The nanoporous aluminum can be used as a combustion catalyst or ignition aid for solid propellants
• Rocket propulsion: The patents describe using the composition with water, including in ALICE propellant configurations, for rocket propulsion