ABSTRACT Electrocatalytic nitrate reduction (NO 3 RR) is a green, environmentally benign, and energy‐efficient approach to ammonia synthesis; however, it is hampered by the competing hydrogen evolution reaction (HER) and complex electron/proton transfer pathways, which lead to low selectivity and sluggish kinetics. Herein, a hierarchical catalyst, denoted as B‐Cu NPs/BNC, was constructed by co‐anchoring Cu single atoms (Cu–N/C) and B‐doped Cu nanoparticles (B–Cu) onto B, N co‐doped porous carbon nanotubes. Comprehensive structural characterizations (XRD, HRTEM, and XAFS) confirmed that interstitial B doping increased the Cu–Cu bond length and lattice spacing, whereas XPS and DFT calculations revealed that the introduction of Cu nanoparticles and B doping induced strong interfacial coupling between Cu atoms and the carbon substrate while regulating the local electronic structures of both Cu single atoms and Cu nanoparticles. As a result, the Cu d‐band center was upshifted, which optimized the adsorption and activation of key intermediates, altered the rate‐determining step, and lowered the corresponding energy barrier. These electronic modulations were found to reduce the energy barrier of the rate‐determining step, suppress side reactions, and inhibit the HER, thereby improving the selectivity toward NH 3 . Consequently, the optimal B‐Cu NPs/BNC‐7 catalyst delivered exceptional NO 3 RR performance, achieving a maximum NH 3 yield of 14.95 mg h −1 cm −2 at −0.9 V versus RHE and a peak Faradaic efficiency of 92.8% at −0.6 V versus RHE in an alkaline electrolyte. Furthermore, when assembled as the cathode in a Zn‐nitrate battery, the catalyst delivered a power density of 18.86 mW cm −2 with excellent cycling stability.
李祥定 et al. (Thu,) studied this question.