First-Principles-Based Screening of Subnanometric Pt n /M-MFI Catalysts for High-Efficient Propane Dehydrogenation

Subnanometric Pt-based catalysts have garnered extensive attention for propane dehydrogenation (PDH) due to their higher activity compared to their nanoparticulate counterparts. Although introducing a second metal component can enhance their stability and tune the catalytic performance, the determination of precise localization of Pt clusters and identification of interactions between the Pt cluster and the second metal remain challenging in experiments, especially in the presence of a catalyst support. This work performed first-principles-based calculations to screen a series of subnanometric Ptn/M-MFI catalysts for PDH, in terms of structure stability, dehydrogenation activity, and propene selectivity. The complete reaction route analysis and microkinetic simulation further validated the reliability of the screening method. The calculation results demonstrate that Pt4/M-MFI candidates with M = Ge4+, Ga3+, Cu2+, Sn2+, and Fe3+ are catalytically more active for PDH, especially for introducing Cu into the MFI framework. Further analysis reveals that the catalytic activity of subnanometric Pt4/M-MFI catalysts for PDH closely correlates with the binding energy and charge transferred between the Pt cluster and the M-MFI zeolite support. The MFI zeolite confinement plays an important role in enabling the secondary-metal promotion of subnanometric Pt clusters. This work provides directional guidance for the future design of high-efficient PDH catalysts.