Modular ammonia-based hydrogen propulsion for drones and ground vehicles

• Modular ammonia-to-hydrogen system for UAVs, ground vehicles, and stationary units. • In-situ catalytic NH₃ decomposition with >90 % conversion efficiency at 650–750 °C. • Pd/Ag and ceramic membranes for high-purity H₂ or mixed-gas ICE operation. • Superior energy density and logistics vs. compressed H₂ and battery-electric systems. • Compatible with nuclear or renewable ammonia production for low-emission energy cycles. Hydrogen logistics remain a bottleneck for sustainable mobility, particularly in off-grid applications where compressed hydrogen and batteries face limits in energy density and infrastructure. This study proposes the first modular ammonia-to-hydrogen propulsion unit engineered for UAVs and ground vehicles. The compact system integrates catalytic cracking of liquid NH₃ at 650–750 °C (Ru/SiO₂ for UAVs, Ni/Al₂O₃ for vehicles), hydrogen purification via Pd/Ag or ceramic membranes, and power conversion through either PEM fuel cells or hydrogen-adapted internal combustion engines. A cartridge-based modular design enables easy replacement of catalysts and membranes, direct adaptation to platform needs, and scalable performance. Modeling indicates that a 200 kg UAV can achieve ranges up to 150 km with 1.2–1.5 kg NH₃ per 100 km. The novelty lies not in the individual processes, but in their first integration into a deployable system architecture optimized for mobility. Coupled with nuclear-sourced ammonia production, this approach outlines a fossil-free pathway that combines high energy density with improved logistics and lifecycle sustainability.