Electrochemical\nNitrogen Reduction: The Energetic\nDistance to Lithium

Energy-efficient electrochemical reduction of nitrogen\n to ammonia\ncould help in mitigating climate change. Today, only Li- and recently\nCa-mediated systems can perform the reaction. These materials have\na large intrinsic energy loss due to the need to electroplate the\nmetal. In this work, we present a series of calculated energetics,\nformation energies, and binding energies as fundamental features to\ncalculate the energetic distance between Li and Ca and potential new\nelectrochemical nitrogen reduction systems. The featured energetic\ndistance increases with the standard potential. However, dimensionality\nreduction using principal component analysis provides an encouraging\npicture; Li and Ca are not exceptional in this feature space, and\nother materials should be able to carry out the reaction. However,\nit becomes more challenging the more positive the plating potential\nis.