Highly efficient catalytic propane dehydrogenation driven by MFI zeolite defect sites.

Cheng, Qingpeng; Yao, Xueli; Ou, Lifeng; Hu, Zhenpeng; Pan, Yu; Zheng, Lirong; Morlanes, Natalia; Abou-Hamad, Edy et al. · Nat Commun · 2025

basic_science · Level V

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Abstract

Propane dehydrogenation (PDH) is a critical technology for propylene production, yet overcoming the trade-off between activity and stability remains a major challenge. Here, we engineer a robust Pt@Sn-MFI catalyst with a wormhole-type structure, featuring highly dispersed Pt clusters robustly anchored by open sites in Sn-MFI, i.e., [SiO]<sub>3</sub> - Sn-O-Pt<sub>n</sub>, complemented by abundant zeolite defects (i.e., Si-OH) in the proximity. This architecture enables a near-thermodynamic equilibrium conversion and a propylene selectivity of ≥98.5%, with the high apparent forward rate coefficient of 1064.5 mol<sub>C3H6</sub> g<sub>Pt</sub><sup>-1</sup>h<sup>-1</sup>bar<sup>-1</sup> and stability for at least 120 h without requiring H<sub>2</sub> or CO<sub>2</sub> co-feeding. Comprehensive characterization, isotope-labeling experiments and theoretical calculations reveal a plausible hydroxy-assisted PDH reaction pathway, wherein the synergy between Pt sites and neighboring hydroxyl groups (i.e., zeolite defects) significantly reduces the energy barrier for H<sub>2</sub> formation via the combination of H in propane adsorbed on Pt sites with H in hydroxyl groups, thereby promoting the PDH process.