Electrochemical scission of dinitrogen under ambient conditions
Project dates: 01. Jan 2021 - 31. Dec 2025
Objective
Present ammonia synthesis, via the Haber-Bosch process, occurs in centralised facilities above 150 bar and above 400 C; it consumes a colossal 1% of our global fossil fuel consumption. Electrolytic ammonia synthesis, i.e. below 100 C and at atmospheric pressures, could be far more attractive: it would be powered by renewable energy and would take place at the point-of-consumption. I have recently made a breakthrough, by demonstrating the first unambiguous and quantitative evidence that dinitrogen electroreduction is possible under ambient conditions on a solid electrode, albeit at low efficiency My aim for NitroScission is to elucidate pathways —at a molecular level— to catalyse the reaction at high efficiency. However, only the most reactive metal or metal nitride surfaces bind to dinitrogen. Such surfaces will bind even stronger to hydrogen or oxygen from water or air. To circumvent these constraints, I will use three strategies:
(i) I will tailor the access of protons to the electrode-electrolyte interface, via in-situ deposited ionic interphases, exploiting recent advances in controlling the reactivity of electrolytes.
(ii) I will tailor the binding to dinitrogen through oxygen-free fabrication and testing of metals and metal nitrides electrodes. By preventing air exposure, my team will gain access to a class of highly reactive electrodes, never previously tested in an electrochemical cell.
(iii) I will use electrochemical looping, to dynamically separate dinitrogen adsorption from its subsequent hydrogenation. These experiments will be enabled by a novel method that allows us to observe gas evolution in real time.
I will combine advanced thin film preparation methods, electrochemical tests, and in operando and ex-situ spectroscopy to establish the design principles for this important reaction. Guided by these unique tools and my scientific leadership, my team will shed unique insight into how to tailor electrode-electrolyte interfaces.