<p></p><p>Exploring electrocatalyst with high activity,
selectivity and stability is essential for development of applicable
electrocatalytic ammonia synthesis technology. By performing density functional
theory calculations, we systematically investigated a series of transition-metal
doped Au-based single atom alloys (SAAs) as promising electrocatalysts for
nitrogen reduction reaction (NRR). For Au-based electrocatalyst, the first
hydrogenation step (*N<sub>2</sub>→*NNH) normally determines the limiting
potential of the overall reaction process. Compared with pristine Au(111) surface, introducing single atom can significantly
enhance the binding strength of N<sub>2</sub>, leading to decreased energy barrier
of the key step, i.e., ΔG(*N<sub>2</sub>→*NNH). According to
simulation results, three descriptors were proposed to describe ΔG(*N<sub>2</sub>→*NNH), including
ΔG(*NNH), <i>d</i>-band center, and
. Eight doped elements (Ti, V, Nb, Ru, Ta, Os, W, and Mo)
were initially screened out with limiting potential ranging from -0.75V to
-0.30 V. Particularly, Mo- and W-doped systems possess the best activity with
limiting potentials of -0.30 V, respectively. Then the intrinsic
relationship between structure and the potential performance was further
analyzed by using
machine-learning. The selectivity, feasibility, stability of these candidates
were also evaluated, confirming that SAA containing Mo, Ru ,Ta, and W could be outstanding NRR electrocatalysts. This
work not only broadens the understating of SAA application in electrocatalysis,
but also devotes to the discovery of novel NRR electrocatalysts.</p><br><p></p>
Free-atom-like d states in single-atom alloy catalysts
