Ammonia (NH3) is a commodity chemical essential to human civilization. Ammonia-based fertilizers are necessary to produce sufficient food for the world’s population, and ammonia may also play a future role in replacing fossil fuels as a carbon-free fuel or carrier of renewable energy. However, almost all ammonia is still produced as it has been for over a century: by catalytically reacting nitrogen (N2) and hydrogen (H2) gases at high temperatures and pressures in the Haber-Bosch process. Due to the extreme reaction conditions and use of fossil fuel-derived H2, ammonia production is currently responsible for about 2% of global carbon dioxide emissions.
What if there was a way to produce ammonia without these serious problems? This is the challenge that Monash University and its spin-out company Jupiter Ionics are tackling head-on. The goal is to produce green ammonia by electrochemical reduction of N2, using water as the source of hydrogen atoms and renewable (e.g. solar) electricity to power the electrolytic process. This has previously been considered extremely challenging to do efficiently: N2 is a very inert molecule and most of the electrical current is misdirected to producing H2 and other unwanted by-products rather than ammonia.
In a recent paper in Nature, the Monash research team lead by Prof Douglas MacFarlane and Dr Alexandr Simonov have shown that near-quantitative current-to-ammonia efficiencies are indeed possible in a lithium-mediated electrochemical ammonia synthesis – provided that the right electrolyte system is used. By using fluorinated lithium salts more commonly found in battery electrolytes, the Monash team was able to control the properties of the electrode-electrolyte interface and suppress undesirable side-reactions. Ammonia could thus be produced continuously, selectively and at excellent reaction rates over multiple days in a simple electrolytic cell.
The commercialisation of this green ammonia technology – initially for sustainable on-farm fertilizer production – is being led by Jupiter Ionics in collaboration with partners such as Fortescue Future Industries and Wesfarmers Chemicals, Energy and Fertilizers. The transformative potential of the technology was recently recognised when Jupiter Ionics was named by Germany’s Falling Walls Foundation as one of the Top 25 Deep Tech start-ups for 2022. We look forward to further successes from the Monash and Jupiter teams as they seek to reimagine ammonia production for a sustainable future.
POF is proud to work with Monash University and Jupiter Ionics to protect green ammonia-related intellectual property.