Optimizing propylene selectivity and stability over Pt–Sn/MgAl₂O₄ catalysts for propane dehydrogenation

Propylene is an essential chemical feedstock, which needs efficient and stable production technology to meet its increasing industrial demand. In this work, the Pt–Sn/MgAl₂O₄ catalysts fabricated via the incipient wetness impregnation method were used for propane dehydrogenation to propylene (PDH). The effect of Sn on reaction performance was investigated to determine the optimal loading amount. The characterization results from XRD, N₂ physisorption, TEM, H₂-TPR, NH₃-TPD, and TGA elucidated the physicochemical characteristic evolution with varied Sn content in the catalysts. The Pt0.3Sn/MgAl₂O₄ achieved the best propane conversion of 40.9% and propylene selectivity of 82.5% at 600 °C. Sn addition promoted Pt dispersion, enhanced metal-support interactions, and inhibited the side reactions. The MgAl₂O₄ support could suppress the coke formation and maintain propylene selectivity. This work demonstrates the Pt–Sn/MgAl₂O₄ catalysts are effective and durable for PDH to meet propylene demand.