Intrinsic Ni <sup>0</sup> –Ni <sup>δ+</sup> Pairs in Anti‐Perovskite NiNNi <sub>3</sub> Act as Hydrogen Radical Emitters for Cu Enabling Promoted Electrocatalytic Nitrate Reduction
Bocheng Zhang, Yanxu Chen, Zechuan Dai, Mingyu Cheng, Pingyi Feng, Buqi Ke, Genqiang Zhang
Abstract
Abstract Electrocatalytic nitrate reduction (NO 3 RR) enables ambient‐condition ammonia production, while ampere‐level application is still limited by the unsatisfactory efficiency due to the insufficient *H supply for rapid *NO hydrogenation. Herein, we tackled this challenge by constructing the NiNNi 3 /Cu heterostructure catalyst that utilizes the substantial electrostatic potential differences derived from the intrinsic Ni 0 –Ni δ+ pairs in anti‐perovskite NiNNi 3 to accelerate the O─H bond cleavage for *H generation, enhancing NO 3 RR. Consequently, the NiNNi 3 /Cu delivers 1.2 A cm −2 with 100 ± 0.7% Faradaic efficiency (FE) at ultralow +0.05 V RHE . The paired electrosynthesis by coupling NO 3 RR with formaldehyde oxidation yields 500 mA cm −2 at a low cell voltage of 0.8 V, with 95% NH 3 ‐FE and 90% formate‐FE. Importantly, industrial‐level application is further demonstrated by a flow cell with 25 cm 2 electrode that delivers 20 A, and produces 64 g NH 4 Cl for 20 h. This work provides a novel rationale for catalyst design that can boost *H density to accelerate hydrogenation kinetics for advanced electrosynthesis applications.