Circumventing CO 2 Reduction Scaling Relations Over the Heteronuclear Diatomic Catalytic Pair.

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