The low NH3 yield rate is a grand challenge for electrocatalytic N2 reduction to NH3. Herein, we report the first uranium single-atom catalyst (SAC) capable of catalyzing the electrochemical N2 reduction reaction (NRR). The uranium SAC features a low limiting potential (<0.5 V) and near-zero free energy changes for N2 adsorption and NH3 desorption. The integration of these merits enables the uranium SAC to afford an unprecedentedly high NH3 yield rate, 3-4 orders of magnitude higher than that of the Ru(0001) surface, which is widely recognized as an excellent NRR electrocatalyst. Further theoretical analysis reveals that the N2 reduction catalyzed by the uranium SAC is synergistically regulated by the d and f electrons of atomic uranium. This work proposes a promising solution (that is, atomically dispersed uranium) to the daunting challenge associated with the low NH3 yield rate, thus enabling the scalable production of NH3 via electrochemical N2 reduction.
Keywords: Ammonia synthesis; Electrocatalysts; N2 reduction reaction; Nitrogen fixation; Single-atom catalysts.