The ability to store renewable energy in the form of chemical bonds in fuels is essential for the realization of a clean energy future. There have been decades of work on the subject of using renewable energy for the electrochemical splitting of water molecules to form hydrogen gas (H2) as a fuel. However, development of infrastructure for the efficient transportation and storage of large quantities of the low-density H2 remains as a major challenge preventing a commercial disruption. Instead of reducing protons (H+) from water to produce H2, therefore, an alternative solution would be to couple the oxidation of water to the reduction of nitrogen gas (N2) from the air and produce ammonia (NH3). NH3 is a higher-density fuel for which the transportation and storage infrastructure is already in place at a national industrial scale.There is plenty of ongoing research into the synthesis of NH3 from renewable N2 and H2, but there have been relatively few studies into efficiently splitting it back apart to recover the H2 fuel. Furthermore, what work has been done in NH3 splitting has largely been in aqueous conditions, which are corrosive to the transportation and storage infrastructure and involve an inherent loss of energy density compared to liquid ammonia (NH3(l)). In this work, we investigate the half reactions involved the electrochemical splitting of anhydrous NH3(l), and propose new Earth-abundant anode and cathode materials to replace the traditionally used noble metals.
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