Rational Design of Transition Metal–Phosphorus Dual-Atom Catalysts in Defective h-BN for CO₂ Hydrogenation and Cycloaddition

Dual-atom catalysts (DACs) have emerged as a promising platform for converting CO 2 into valuable chemicals, addressing critical energy and environmental challenges. Here, we theoretically designed M 1 -P 1 /V BN catalysts by embedding single transition metal (M = Ir, Rh, and Co) and phosphorus atoms into defective h-BN. Extensive first-principles calculations were employed to investigate the mechanisms of CO 2 thermal hydrogenation to HCOOH and CO 2 cycloaddition with propylene oxide (PO) to produce propylene carbonate (PC). The metal–phosphorus dual-active sites were predicted to facilitate simultaneous activation and adsorption of CO 2, H 2, and PO, enabling detailed exploration of the reaction pathways. By combining static electronic structure calculations and microkinetic simulations, this work demonstrates that M 1 -P 1 /V BN sheets show excellent catalytic performance for both reactions under relatively mild conditions, particularly for CO 2 hydrogenation on Co 1 –P 1 /V BN and cycloaddition on Rh 1 –P 1 /V BN . Stability analysis confirms the robustness of transition-metal-doped M 1 -P 1 /V BN systems. Notably, the binding strength of small molecules strongly correlates with metal type, and a strong linear correlation was observed between the adsorption free energies of reactive intermediates. This study offers valuable theoretical insights into the thermocatalytic mechanisms of CO 2 hydrogenation and cycloaddition mediated by M 1 -P 1 /V BN catalysts, laying a foundation for designing multifunctional DACs to advance CO 2 utilization technologies.