The Haber Bosch process has allowed for fertilizer production on a global scale, facilitating the explosive growth in human population since its implementation. Each year, the process consumes over 1% of the entire global energy supply and releases ~450 million metric tons of CO2 due to its dependence on fossil fuels for H2 production. In this work we propose an alternative pathway toward sustainable ammonia synthesis via an electro-thermochemical cycling process, which circumvents the high pressure and H2 gas requirements of the Haber Bosch process by using electricity and H2O, and thus may be implemented with renewable energy, locally where the ammonia fertilizer is used. The process comprises three distinct steps of surface preparation, nitrogen activation, and ammonia synthesis which can be combined and cycled for continuous ammonia production. Theoretical considerations elucidate the feasibility and general applicability of this cycle. The process steps are characterized with specific electrochemical and materials chemistry techniques. Ammonia is quantified by ultra violet-visible colorimetric analysis and confirmed to be from N2 via isotopic labeling in Fourier transform infrared radiation studies. We report a current efficiency of 88.6% for ammonia production via this process.

Electro-thermochemical cycling process for high-yield ammonia synthesis from N2 and H2O at atmospheric pressure

253rd National Meeting (2017)

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