Size-Dependent Structural Features of Subnanometer PtSn Catalysts Encapsulated in Zeolite for Alkane Dehydrogenation

Identification of the most efficient configuration of subnanometer bimetallic clusters is of great importance for the rational design of bimetallic catalysts but remains challenging due to the difficulty to construct the appropriate model systems. Here, we have accommodated subnanometer Pt/Sn sites, spanning from metal single atoms to bimetallic clusters in the 10MR sinusoidal channels of pure-silica MFI-type zeolite, which are employed as model catalysts to identify the optimal configuration of subnanometer PtSn sites for catalyzing an alkane dehydrogenation reaction. According to the electron microscopy and spectroscopy characterization results, the structural configuration of the bimetallic PtSn species in MFI zeolite varies with the Pt loading, which influences their catalytic performances for the propane dehydrogenation reaction. Furthermore, theoretical calculations are performed to understand the structural features of various PtSn species and their catalytic behavior for propane dehydrogenation, providing insights into the structure-reactivity relationships of subnanometer PtSn catalysts confined in zeolite structures.