Advancements in thermocatalytic ammonia decomposition for hydrogen production

Ammonia emerges a highly promising carbon-free hydrogen source, presenting a potential solution to the inherent challenges of hydrogen storage and transportation. Currently, the application of thermocatalytic ammonia decomposition for hydrogen production has become a focal point of scientific inquiry. Although several noble metal catalysts and membrane reactors have demonstrated commendable thermocatalytic performance, significant challenges such as high costs and substantial energy consumption persist. This paper first summarizes the current research status of various conventional thermocatalysts for ammonia decomposition, with a particular emphasis on the investigation of active components and supports. Recent findings indicate that state-of-the-art ruthenium-based catalysts can achieve over 90% conversion at temperatures below 400°C, with nearly 100% conversion at 450°C. Additionally, it reviews current research status of a novel self-heating catalyst. Furthermore, this paper collates findings in the domain of ammonia decomposition equipment and systems, emphasizing advancements in pertinent materials, reactor, and system. Subsequently, a brief evaluation of the economic viability of current thermocatalytic ammonia decomposition reveals that ammonia feedstock constitutes over 50% of the overall hydrogen production cost. Finally, we highlight that to firmly establish ammonia as a carbon-free hydrogen source, it is imperative to develop efficient non-noble metal catalysts and highly effective ammonia decomposition reaction systems capable of utilizing renewable energy sources. We believe that this approach represents an inevitable path forward in realizing ammonia’s vast potential as a sustainable and environmentally friendly hydrogen source.