Electrocatalytic C–N coupling on hybrid double-atom catalysts for methylamine synthesis from CO2 and NO

Abstract

Electrochemical synthesis using carbon dioxide (CO₂) and nitric oxide (NO) offers a sustainable method for producing valuable chemicals like methylamine, yet the combined process remains underexplored, particularly in catalyst design for effective C–N coupling. Here, we present a γ-graphdiyne (GDY) −supported CuCo hybrid double atom catalyst (CuCo@GDY), designed and evaluated for the electrochemical synthesis of methylamine from CO₂ and NO by density functional theory (DFT) and ab initio molecular dynamics (AIMD) calculations. CuCo@GDY demonstrates exceptional stability and catalytic activity, with synergistic Cu and Co sites that efficiently adsorb and activate NO and CO₂. A new mechanism for methylamine synthesis is proposed on CuCo@GDY, emphasizing the critical role of *CH₂O and *NH₂OH intermediates in enabling effective C–N coupling. The methylamine formation exhibits low thermodynamic barriers of 0.75 eV and dynamic barriers of 1.10 eV on CuCo@GDY. It also effectively suppresses the hydrogen evolution reaction (HER) and other side reactions, enhancing methylamine selectivity. Its combination of single-atom and hybrid double-atom effects significantly enhances hydrogenation and C–N bond formation, leading to high selectivity and catalytic activity for methylamine production. Our findings provide a scalable approach for sustainable methylamine production, offering new insights into hybrid double atom catalyst design and advancing electrocatalytic C–N coupling with broad environmental and energy implications.