Circumventing CO₂ Reduction Scaling Relations Over the Heteronuclear Diatomic Catalytic Pair

In the electrochemical CO₂ reduction reaction (CO₂RR), CO₂ activation is always the first step, followed by the subsequent hydrogenation. The catalytic performance of CO₂RR is intrinsically restricted by the competition between molecular CO₂ activation and CO₂ reduction product release. Here, we design a heteronuclear Fe₁-Mo₁ dual-metal catalytic pair on ordered porous carbon that features a high catalytic performance for driving electrochemical CO₂ reduction to CO. Combining real-time near-ambient pressure X-ray photoelectron spectroscopy, operando ⁵⁷Fe Mössbauer spectroscopy, and in situ attenuated total reflectance surface-enhanced infrared absorption spectroscopy measurements with density functional theory calculations, chemical adsorption of CO₂ is observed on the Fe₁-Mo₁ catalytic pair through a bridge configuration, which prompts the bending of the CO₂ molecule for CO₂ activation and then facilitates the subsequent hydrogeneration reaction. More importantly, the dynamic adsorption configuration transition from the bridge configuration of CO₂ on Fe₁-Mo₁ to the linear configuration of CO on the Fe₁ center results in breaking the scaling relationship in CO₂RR, simultaneously promoting the CO₂ activation and the CO release.