Selective acetylene hydrogenation over single metal atoms supported on Fe₃O₄(001): A first-principle study

Supported single-atom catalysts (SACs) have gained increasing attention for improved catalytic activity and selectivity for industrially relevant reactions. In this study, we explore the hydrogenation of acetylene over single Pt, Ru, Rh, Pd, and Ir atoms supported on the Fe₃O₄(001) surface using density functional theory calculations. The thermodynamic profile of H diffusion is significantly modified by the type of single metal atoms used, suggesting that H spillover from the single atom dopant to the Fe₃O₄(001) surface is favored and will likely lead to high H coverages of the functioning catalyst. Correspondingly, as the surface H coverage increases, the important desorption step of ethylene becomes energetically competitive against the detrimental hydrogenation steps of ethylene to ethane. A kinetic model is employed to explore how the activity and selectivity of SACs toward ethylene production change as a function of mass of the catalyst loaded into a flow reactor. Overall, we show that the selectivity of SACs toward ethylene production can be tuned by considering the proper type of metal and controlling the redox state of the support.