Highly efficient catalytic propane dehydrogenation driven by MFI zeolite defect sites
Qingpeng Cheng, Xueli Yao, Lifeng Ou, Zhenpeng Hu, Yu Pan, Lirong Zheng, Natalia Morlanés, Edy Abou‐Hamad, Xingang Li, Yu Han, Jorge Gascón
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]3 − Sn−O−Ptn, 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 molC3H6 gPt−1h−1bar−1 and stability for at least 120 h without requiring H2 or CO2 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 H2 formation via the combination of H in propane adsorbed on Pt sites with H in hydroxyl groups, thereby promoting the PDH process. Propane dehydrogenation (PDH) is critical for propylene production, yet overcoming the trade-off between activity and stability remains a challenge. Here a robust Pt@Sn-MFI catalyst is developed for PDH, leveraging the synergy between Pt and hydroxyl sites.