Molecular simulations studies of ammonia formation mechanism in plasma reactors

Diego Gomez-Gualdron

dgomezgualdron@mines.edu

This projects fall under the umbrella of a larger NSF-funded project looking to develop a carbon-free method to produce ammonia (NH3) from N2 and H2. For context, consider that 1% of the world CO2 emissions come solely from  synthesizing ammonia, which is a critical chemical for fertilizers and is estimated to enable feeding  ~50% of the world's population. The larger project aims to use plasma catalysis as the way to decarbonize ammonia synthesis, where the plasma would be powered with renewable electricity. What the plasma does is break some fraction of N2 in the gas phase, so that the catalyst does not have to worry about breaking the N2, but only on adding H atoms to atomic nitrogen until NH3 is formed. The problem is that the exact mechanism by which all these processes happen is not understood, so the knowledge to improve the process to make it economically viable is not yet available. This MURF project aims to use molecular simulations in Mines supercomputers to elucidate the rates at which N and H plasma radicals react with reaction intermediates on catalyst surfaces. These reactions are nearly impossible to probe experimentally, so these simulations (used as a theoretical microscope) provide about the only means to obtain valuable insights about them. Thus the simulations the student will run are valuable on their own, but also fit into the larger project as they will provide crucial rate data to be fed to larger kinetic models used by the group in our efforts to find better reaction conditions and catalysts for the process.

Grand Challenge: Manage the nitrogen cycle.

• https://historyofyesterday.com/the-chemists-who-saved-the-world-from-world-hunger-25359a71c33c
• https://www.theguardian.com/business/2021/oct/20/global-energy-crisis-famine-production
• https://pubs.acs.org/doi/pdf/10.1021/acssuschemeng.1c05660

 

Diego A Gomez-Gualdron, dgomezgualdron@mines.edu