Recent Advances and Challenges in Ammonia-Hydrogen Energy Conversion

Recently, hydrogen energy has emerged as a key pathway to address the change of global climate and the intermittency of renewable energy, demonstrating significant strategic value in new energy storage systems. However, hydrogen is required to be liquefied at extremely low temperatures or stored in gaseous form under high pressure. Both methods are energy-consuming and difficult to operate. Ammonia (NH₃) is recognized as an ideal hydrogen carrier due to its high hydrogen density as well as mature infrastructure for storage and transportation, which has the potential to further reduce the cost of hydrogen utilization. In this context, the integrated ammonia-hydrogen energy system composed of synthetic ammonia and ammonia decomposition not only contributes to achieving low-carbon energy transition goals but also supports distributed power generation applications. This review systematically summarizes recent advances and challenges in key technologies for ammonia synthesis and decomposition, providing insights for the development of novel energy storage systems.