Ammonia (NH3) is a highly-produced inorganic chemical with a global output of 235 million tons in 2021. With the growing global population, it’s projected that the demand for ammonia will increase to 350 million tons annually by 2050. Most of the ammonia produced worldwide is used in fertilizer production, accounting for over 80% of the total production. Ammonia also has a range of other applications, including as a refrigerant gas, in water purification, and in the textile industry. However, there is a growing interest in producing ammonia from green sources to meet the net-zero challenges in the fertilizer industry by 2050, as the current reliance on methane, a fossil fuel, is a major concern.
The majority of ammonia is produced through the Haber-Bosch process, which has been in use for over a century.
The majority of ammonia is produced through the Haber-Bosch process, which has been in use for over a century. This process combines nitrogen from air with hydrogen from steam reforming to create ammonia at high pressure and temperature. While the Haber-Bosch process has been crucial in boosting the world’s population through increased food production, it also has significant environmental drawbacks, including high greenhouse gas emissions (2.16 kg of carbon dioxide per 1 kg of ammonia) and energy usage of 30 GJ per 1-tonne ammonia. Moreover, integrating the process with renewable energy sources is challenging.
One promising approach is the electrochemical Nitrogen Reduction Reaction (NRR).
Researchers worldwide are seeking alternative methods to produce ammonia sustainably by connecting the reaction to renewable energy sources. One promising approach is the electrochemical Nitrogen Reduction Reaction (NRR). In this method, researchers use a Li+-mediated electrochemical cell to reduce N2 to lithium nitride and then use a proton shuttle molecule to produce ammonia. Despite some advances in ammonia production using NRR, the challenge of achieving high yield rates and stable operation over a reasonable time frame remained for decades.
a recent breakthrough came from a research team headed by Professor Doug MacFarlane at Monash University in Australia
However, a recent breakthrough came from a research team headed by Professor Doug MacFarlane at Monash University in Australia, who discovered a way to produce ammonia at room temperature, at high rates and efficiencies, using an electrochemical nitrogen reduction reaction (NRR) with phosphonium salt as a proton carrier. The team initially achieved reasonable progress with a Pt on Ti-mesh anode, Cu cathode, and LiBF4 electrolyte and reported a faradaic efficiency (FE) of 78%. And as the latest advancement, the team succeeded to achieve significant progress by reporting 100% faradaic efficiency with a Ni wire cathode and NTf2- electrolyte with ethanol as the proton carrier.
The Monash process marks a significant step towards the Power-to-x movement, connecting global key chemical processes with renewable energy. This development is almost as important as the Haber-Bosch process, which changed the course of history by helping with ammunition production during World War I and later preventing mass starvation and increasing the world population.