Highly Dispersed Molybdenum Carbide Clusters Enable Efficient CO ₂ Hydrogenation

ABSTRACT The reverse water–gas shift (RWGS) offers a promising route to convert CO 2 into CO, a vital feedstock for chemical synthesis. However, the reaction is strongly endothermic and only driven by marginal entropy increasing, requiring high temperature to achieve appreciable CO yields. At such conditions, non‐noble metal catalysts suffer from low activity, and noble metals, though being more active, are prone to deactivation. Here, we report that sub‐nanometer molybdenum carbide (MoC) clusters supported on carbon enable highly efficient and stable RWGS catalysis without noble metals. The catalyst achieves CO formation rate of 1.26 mol CO mol Mo −1 s −1 and mass‐specific activity of 1028 µmol CO g cat −1 s −1 , with near 100% CO selectivity and exceptional stability. Characterizations reveal that MoC spontaneously disperses as sub‐nanometer clusters on support, maximizing the density of coordinatively unsaturated surface sites. These sites facilitate efficient CO 2 adsorption/activation, enabling rapid removal of surface oxygen species. Density functional theory calculations show that highly dispersed MoC sites exhibit distinct local environment, which accounts for weak Mo–O binding and enhances overall catalytic power. This work demonstrates a noble‐metal‐free catalyst that couples high activity, selectivity, and stability with exceptional atom efficiency, offering robust and sustainable strategy for CO 2 valorization.