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