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.