Thermocatalytic Ammonia Decomposition – Status and Current Research Demands for a Carbon‐Free Hydrogen Fuel Technology

Abstract Hydrogen storage materials and technologies are deemed as the cornerstone towards a world economy less reliant on, and ultimately independent of fossil resources. Ammonia is considered among the most efficient carbon‐free hydrogen carriers because of its relatively high gravimetric and volumetric hydrogen storage capacities and, equally important, ease of transport and storage. In addition, the well‐established chemical production of ammonia (preferably a green Haber‐Bosch process) would accelerate the immediate introduction of hydrogen into energy infrastructure. Thermocatalytic decomposition of ammonia yields clean, CO x ‐free hydrogen, but is energy intensive and currently performed with expensive Ru‐based catalysts. The development of more efficient catalysts based on more abundant and cheaper elements is indispensable for future wide‐scale industrial application. Therefore, the conceptualization of strategies and challenges for material developments, study and optimization of ammonia decomposition catalysts as well as their in situ/operando characterizations are pivotal aspects to be considered.