Modulating the Degree of the Dehydrogenation Reaction of Long-Chain Alkanes via Tuning the Pt-Based Catalytic Ensembles

The upgrading of long-chain alkanes (C5−C10+) to alkenes and aromatics is critical for adapting to the shifting industrial demand from transportation fuels toward commodity chemicals. Unlike light alkane dehydrogenation, the conversion of long-chain alkanes involves an intricate reaction network, complicating the design of selective catalysts. Herein, we engineered PtSn nanoclusters confined within dealuminated Beta zeolite as model catalysts for the non-oxidative conversion of n -octane. By mitigating support acidity to suppress cracking, the confined PtSn sites achieve an n -octane conversion of 23% with a selectivity to octenes of 73%, outperforming the monometallic Pt analogue. A synergistic combination of experimental characterization and theoretical modeling reveals that Sn incorporation modifies the Pt electronic structure and fragments contiguous Pt ensembles. This geometric isolation suppresses undesired C−C cleavage and hydrogenolysis while optimizing the binding energies of reactive intermediates, thereby shifting the kinetic control toward selective dehydrogenation. This study establishes a structure−reactivity relationship for long-chain alkane activation on bimetallic sites, offering insights for controlling dehydrogenation pathways through precise ensemble and microenvironment engineering.