Enhancement of propane dehydrogenation performance of Pt-based catalyst: Confinement of Mo-modified Pt in silicalite-1 zeolite

• Pt-Mo nanoclusters were confined in Silicalite-1 zeolite by in situ hydrothermal synthesis and direct hydrogen reduction. • Mo incorporation enhanced Pt dispersion and sintering resistance. • The catalyst achieved 97 % propylene selectivity and 43 % propane conversion at 550 °C. • Excellent stability was maintained after four regenerations with low deactivation rate. • Pt-Mo synergy enhanced regenerability and coking resistance of the PDH catalyst. The present study investigated a novel bimetallic Pt-Mo catalyst encapsulated within Silicalite-1 zeolite for propane dehydrogenation (PDH). The catalyst was synthesized via in situ hydrothermal crystallization, followed by direct high-temperature H 2 reduction without conventional calcination, leading to uniform encapsulation of Pt nanoparticles within the zeolite framework and simultaneous removal of the template and organic ligands. PDH performance was evaluated in a continuous-flow fixed-bed microreactor. Comprehensive characterizations (XPS, CO-DRIFTS, NH 3 -TPD, Raman, etc.) reveal that Mo incorporation in 0.4Pt@S-1 catalyst significantly enhances propane conversion while maintaining high propylene selectivity. Moreover, the bimetallic 0.4PtXMo@S-1 catalyst with 0.1 % Mo doping achieved an outstanding performance at 550 °C and a WHSV of 5.49 h −1 (propane conversion: 43 %, propylene selectivity: 97 %, propylene formation rate: 16.27 mol C3H6 ·g Pt -1 ·h −1 ). The prepared catalyst possessed favorable stability and regeneration performance, showing a deactivation rate of only 0.001454 h −1 after four reaction-regeneration cycles. This enhancement is attributed to synergistic effects arising from Mo incorporation, which promotes Pt nanoparticle dispersion, modulates Brønsted /Lewis acidity, and facilitates interfacial electron transfer between Pt and Mo species. These findings highlight the role of Pt-Mo interactions within zeolite frameworks, providing new insights for designing efficient and stable PDH catalysts.