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

Dual-atom catalysts (DACs) have emerged as a promising platform for converting CO into valuable chemicals, addressing critical energy and environmental challenges. Here, we theoretically designed M-P/V 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 thermal hydrogenation to HCOOH and CO 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, H, and PO, enabling detailed exploration of the reaction pathways. By combining static electronic structure calculations and microkinetic simulations, this work demonstrates that M-P/V sheets show excellent catalytic performance for both reactions under relatively mild conditions, particularly for CO hydrogenation on Co-P/V and cycloaddition on Rh-P/V. Stability analysis confirms the robustness of transition-metal-doped M-P/V 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 hydrogenation and cycloaddition mediated by M-P/V catalysts, laying a foundation for designing multifunctional DACs to advance CO utilization technologies.