Enhanced catalytic stability and structural evolution of Rh-BN interface in dry reforming of methane under intensified CO₂ partial pressure

Strong metal-support interaction (SMSI) is a crucial factor that determines the structure and performance of a supported metal catalyst. Herein, the SMSI effect of Rh nanoparticle catalyst supported on h-BN is investigated in the dry reforming of methane (DRM) reactions with different CO₂/CH₄ ratios. The catalyst characterization results demonstrate that the SMSI effect allows the Rh nanoparticles to be encapsulated by BO_x overlayers under DRM reaction conditions (CO₂/CH₄ = 1/1), which prevents the interaction between the reactants and metal centers for causing rapid deactivation. By increasing the partial pressure of CO₂ (CO₂/CH₄ = 3/1), Rh/BN exhibits significantly enhanced activity and long-term stability in the DRM reaction. CO₂ or H₂O in the reactive atmosphere can effectively etch the BO_x overlayers for steadily exposing the active Rh-BN interface sites, as evidenced by the characterization. This observation extends the understanding of the SMSI effect at the interfaces between metal and non-oxide support.