Rational synthesis of dual-atom catalysts for optimized thermochemical CO2 reduction

Dual-atom catalysts offer high atom utilization and synergistic inter-atom interactions, yet their use in high-temperature thermocatalysis remains largely unexplored due to challenges in achieving structurally homogeneous and robust active sites. Herein, we report a scalable coordinated bottom-up strategy for the synthesis of a Cu-Ni dual-atom catalyst supported on nitrogen-doped carbon (CuNi-DAC), featuring a well-defined N₂Cu-N₂-NiN₂ configuration in which each metal atom is coordinated to four nitrogen atoms and bridged by two nitrogen atoms. Under reverse water-gas shift reaction conditions, CuNi-DAC achieves CO₂ conversion approaching thermodynamic equilibrium with nearly 100% CO selectivity. Critically, CuNi-DAC maintains its atomic structure and catalytic performance up to 600 °C over repeated cycles, while reference catalysts including Cu-SAC and Ni-SAC experience severe deactivation along with metal sintering. Comprehensive ex-situ and in-situ characterizations, integrated with theoretical calculations, reveal that d-d orbital coupling and electronic polarization between adjacent Cu and Ni centers enhance selective CO₂ reduction to CO product, while reinforcing metal-support interactions to mitigate sintering. The in-depth mechanistic insights and the scalable synthesis provide a blueprint for the rationally designing next-generation dual-atom catalysts with enhanced efficiency, stability, and tailored activity for target chemical transformations.