Efficient Cu─Co Dual‐Sites in Cobalt Oxide Nanoboxes for Electrocatalytic Reduction of Low‐Concentration NO to NH 3

Abstract The electrocatalytic conversion of nitric oxide (NO) to ammonia (NH 3 ) epitomizes an advanced approach in NH 3 synthesis, crucial for efficiently converting low‐concentration industrial NO exhaust and contributing significantly to environmental preservation. Catalyst design remains one pivotal element in addressing this challenge. Here, efficient Cu─Co dual active sites embedded in hollow cobalt oxide nanoboxes are created for the electrocatalytic low‐concentration NO reduction reaction (NORR). Cu‐modified cobalt oxide (Cu‐Co 3 O 4 ) and its heterophase interface with copper oxide (Cu‐Co 3 O 4 /CuO) both exhibit over 93% Faraday efficiency for NH 3 synthesis, with a yield reaching up to 59.10 µg h −1 mg cat −1 at −0.4 V versus reversible hydrogen electrode by utilizing simulated industrial NO exhaust (1 vol %) as the feedstock, surpassing those of pure cobalt oxide and some reported catalysts. Theoretical calculations and NO temperature‐programmed desorption experiments demonstrate that the incorporation of Cu significantly enhances NO adsorption and reduces the energy barrier of the rate‐determining step. The integration of Cu‐Co 3 O 4 and Cu‐Co 3 O 4 /CuO within the cathode of the Zn–NO battery demonstrates a notable power density of 2.02 mW cm −2 , highlighting a propitious direction for investigating highly efficient conversion of low‐concentration NO exhaust gas.