Single atomic cerium sites anchored on nitrogen-doped hollow carbon spheres for highly selective electroreduction of nitric oxide to ammonia.

Single atomic Ce sites confined in N -doped hollow carbon spheres are developed as an efficient catalyst for catalyzing NO reduction to NH 3 with maximal Faradaic efficiency of 91 ± 2% and a yield rate of 1023 ± 6 μg h−1 cm−2, exceeding the Ce nanoclusters counterpart. Furthermore, a Zn–NO battery is constructed to yield NH 3 and supply electricity as well. [Display omitted] Electrocatalytic nitric oxide reduction reaction (NORR) at ambient environments not only offers a promising strategy to yield ammonia (NH 3) but also degrades the NO contaminant; however, its application depends on searching for high-performance catalysts. Herein, we present single atomic Ce sites anchored on nitrogen-doped hollow carbon spheres that are capable of electro-catalyzing NO reduction to NH 3 in an acidic solution, achieving a maximal Faradaic efficiency of 91 % and a yield rate of 1023 μg h−1 mg cat. −1 at –0.7 V vs RHE for NH 3 formation, both of which outperform these on Ce nanoclusters and approach the best-reported results. Meanwhile, the single atomic Ce catalyst shows good structural and electrochemical stability during the 30-h NO electrolysis. Furthermore, when the single atomic Ce catalyst was used as cathodic material in a proof-of-concept of Zn–NO battery, it delivers a maximal power density of 3.4 mW cm−2 and a high NH 3 yield rate of 309 μg h−1 mg cat. −1. Theoretical simulations suggest that the Ce-N4 active moiety can not only activate NO molecules via a strong electronic interaction but also reduce the free energy barrier of *NO transition to *NOH intermediate as the limiting step, and therefore boosting the NORR kinetics and suppressing the competitive hydrogen evolution. [ABSTRACT FROM AUTHOR]