Oxidative dehydrogenation of C₂H₆and CO₂mediated by Rh_xNb_y − (x + y = 5) clusters

Oxidative dehydrogenation (ODHE) of C₂H₆ and CO₂ to generate C₂H₄ and CO is industrially important but remains a long-standing challenge due to the complexity of this co-conversion and the thermodynamically stable and kinetically inert nature of both reactants. Herein, we theoretically demonstrated that the Rh_xNb_y⁻ (x + y = 5) bimetallic clusters can drive the ODHE of C₂H₆ and CO₂ to produce C₂H₄, CO, and H₂O. The results indicated that the desorption of C₂H₄ and CO takes place under mild conditions, and the increased number of Rh atoms in Rh_xNb_y⁻ leads to progressively more difficult C₂H₄ desorption. In contrast, the formation and evaporation of H₂O represent the kinetically and thermodynamically demanding pathway to govern the overall efficiency of ODHE. This finding provides an integrated picture to understand the fundamental mechanisms of the ODHE of C₂H₆ and CO₂. The selective release of C₂H₄ and the rate-determining behaviour of H₂O generation were rationalized.