Integrating an increasing amount of energy from renewable sources, such as sun and wind, into the energy system is challenging since it is often produced far from densely populated areas and has a natural variability (intermittency). One solution is to store and transport this energy as molecules. Such molecular energy carriers should not release carbon dioxide when their energy is used, and alternatives to the classical, carbon-containing, energy carriers are thus needed. One of the most attractive alternatives is ammonia, which is easily compressed to a non-explosive liquid with almost twice the energy density of liquid hydrogen. Like hydrogen, ammonia can be converted to electricity or used directly as fuel in combustion engines. However, to realize ammonia’s potential as a sustainable carbon-free energy carrier, a major challenge must be overcome: Its current energy-intensive production process must be replaced by a more benign process based on renewable electricity.
To achieve such a process, the team will take inspiration from the bacterial nitrogenase enzymes, which produce ammonia efficiently from water and atmospheric nitrogen at room temperature. Enzymes are biological catalysts that speed up chemical reactions without themselves being consumed. The key catalytically active component of nitrogenase consists of molybdenum, a metal. The team will develop industrially compatible catalysts based on molybdenum using a combination of computer-based prediction and high-throughput, robot-based experimentation. During the catalyst development, the energy driving the ammonia process will come from a chemical compound. A key challenge will be to adapt the process to run on electricity. If achieved, such a process could provide worldwide abundant and sustainable ammonia for fertilizers, fuel, and energy, and thus contribute to a green economic, industrial, and societal transition.
To meet the United Nations’ climate targets, the contribution from renewable energy and low-carbon solutions to the world’s energy mix must increase drastically. Much of this increase will come from solar and wind power, and fair amounts of this electricity will be produced far from densely populated and industrialized areas. Making this massive and largely remotely-produced energy resource accessible at times and locations where it is highest in demand, defines a strong drive for reliable, efficient and safe technology for converting, storing and transporting green energy commodities. Part of this technology will be based on hydrogen. However, due to the hazards of hydrogen, its low energy density, and the costs of compressing and liquifying hydrogen, ammonia emerges as an attractive carbon-free energy vector. The main challenge to realizing ammonia’s potential is to replace its current high-temperature, high-pressure production process with a more benign process based on renewable electricity.
To develop such a process, we have assembled a team of leading academic researchers in chemistry and company experts on renewable energy and maritime transport solutions. We will develop electrocatalytic processes for direct and benign water-based ammonia production. Superior electrocatalytic production efficiency will be achieved by computationally guided development of active and stable catalysts for water-based nitrogen fixation and implementation thereof in cells for electrocatalytic ammonia production. The project involves state-of-the-art and emerging methodology and expertise ranging from molecular design, via high-throughput synthesis and experimentation, to electrocatalysis. Finally, a successful electrocatalytic process could provide worldwide abundant and sustainable ammonia for fertilizers, fuel, and energy, and thus contribute to a green economic, industrial, and societal transition.