CO₂ Laser‐Stabilized Ni‐Co Dual Single‐Atomic Sites for Energy Generation and Ammonia Harvesting

Abstract Dual single‐atom catalysts (DSACs) hold immense potential in electrochemical nitrate (NO₃⁻) reduction (EcNR) as a sustainable replacement to the Haber–Bosch process for the production of ammonia (NH₃). However, challenges such as synthesis complexity, low purity, scalability, and stability have hindered their practical application. Herein, a rapid and scalable method is introduced to stabilize low‐cost 3d transition metals (Ni and Co) as DSACs on Ti₃C₂T_x MXene in 10 min using continuous‐wave CO₂‐laser irradiation. Ni²⁺ and Co²⁺ ions are chelated and stabilized as single atoms onto an L‐tryptophan‐modified Ti₃C₂T_x surface via metal─O and metal─N bonds, forming Ni‐single atom catalyst (SAC)/MXene, Co‐SAC/MXene, and NiCo‐DSAC/MXene. This approach enhances MXene properties, enabling the synthesis of efficient atomic‐level electrocatalysts. Potential‐resolved in situ Raman spectroelectrochemistry and density functional theory reveal that EcNR proceeds through NO₃⁻ reduction to ^*NO₂, ^*NO, ^*NH, and ^*NH₂ intermediates, ultimately forming NH₃ via final protonation step. This process exhibits a low limiting potential of −0.37 V, with ^*NO₂ protonation identified as the critical step. NiCo‐DSAC/MXene exhibited superior EcNR performance for NH₃ production in 1.0 M potassium hydroxide with sustained multiple cyclic stability. Furthermore, this catalyst is integrated into a Zn–NO₃⁻ a battery that simultaneously removes NO₃⁻, generates energy, and synthesizes NH₃.