Article

Hydrogen has emerged as a viable alternative to petroleum, particularly in the transportation sector, where hydrogen-powered trains have begun commercial operations within the European Union. The pioneering hydrogen fuel cell train, which commenced operational service near Frankfurt, Germany, in 2018, utilized gray hydrogen produced for industrial purposes.

While this gray hydrogen offered a 50% reduction in environmental impact, concerns about its overall sustainability persisted. Consequently, the transition towards green hydrogen, generated from renewable energy sources, aims for a complete 100% environmental footprint reduction.

Despite its promise, hydrogen faces significant challenges, notably in storage, transportation, and safety, highlighted by the tragic 1937 explosion in Manchester Township, New Jersey, which claimed 36 lives. To mitigate these risks, ammonia has emerged as a safer alternative. Global ammonia production stands at approximately 200 million tons annually, primarily for chemical fertilizers, and its properties allow for easier storage and transportation compared to hydrogen.

Recent advancements have demonstrated that ammonia can be synthesized from abundant resources such as nitrogen and water, using light to facilitate the chemical reaction. This innovative method, reported by Professor Yoshiaki Nishibayashi and his team from the University of Tokyo, represents a breakthrough in ammonia production, allowing for synthesis at room temperature and pressure. This research, published in the British journal *Nature Communications* in May 2025, underscores ammonia's potential as a carbon-neutral fuel that also poses lower explosion risks.

In conclusion, the shift towards ammonia could redefine sustainable energy solutions, offering a safer, more manageable alternative to hydrogen while enhancing the viability of green energy initiatives. As research progresses, the role of ammonia in global energy dynamics is poised to expand significantly.