Experimental Exploration of An Ammonia Cracking Power Generation System for Electric Aircraft Propulsion

The aviation sector faces growing pressure to reduce carbon emissions, and electric propulsion systems (EPS) based on proton exchange membrane fuel cells (PEMFCs) provide a promising path toward sustainable, zero-carbon aviation. However, challenges related to hydrogen storage and transport have hindered the practical implementation of such systems. Ammonia (NH 3 ), with high energy density, convenient storage and transport, and carbon neutrality, has emerged as an attractive hydrogen carrier. This study proposes and experimentally validates a compact NH 3 cracking power generation system tailored for EPS through laboratory-scale exploration, engineering-scale validation, and system-level evaluation. The system delivers a maximum power output of 30 kW and comprises a custom-designed multifunctional NH 3 cracking reactor with integrated heat recovery, a temperature swing adsorption (TSA) purification unit, and PEMFC stacks. To meet practical application needs, this study screens and optimizes a commercially available 1% Ru–Ni/Al 2 O 3 catalyst, achieving over 99% NH 3 conversion under realistic conditions. The TSA unit reduces NH 3 concentration to below the detection limit, ensuring stable PEMFC performance with a single-stack maximum power output of 5.3 kW. Simulation results further show that the multi-stage thermal management increases the propulsion usable net electrical efficiency to 20.52%, and further raises the overall energy efficiency to 28.33% when the low-grade recovered heat is assumed fully usable. The optimized system achieves a gravimetric energy density of 692.7 W·h·kg −1 and a hydrogen storage capacity of 6.7 wt% when equipped with five NH 3 tanks, each containing 22.7 kg of NH 3 . This work demonstrates an NH 3 -powered PEMFC EPS for aviation, offering both experimental validation and theoretical guidance for NH 3 -fueled propulsion technologies. The study provides system-level insights into design, integration, and performance optimization, supporting the future development of electrified aviation and related zero–carbon distributed energy systems.