(560dg) Highly Stable and Coke Resistant Pt-Mn/K-Al2O3 Catalyst for Propane Dehydrogenation Reaction

Dehydrogenation reaction is one of the promising process for the production of propylene. Several processes are commercialized where Pt-Sn based catalyst are used however the catalyst suffers from faster deactivation due to coke deposition and metal sintering at high temperature. Thereby, requires frequent regeneration step imposing an additional operational cost to the process. There has a great effort put by the researchers to improve the performance of this catalyst and similar system to achieve high selectivity of propylene and increase the lifetime of the catalyst. Considering only Pt/Al2O3 leads to side reactions such as hydrogenolysis and cracking. Promotion of Pt with other metal /metal oxides helps to suppress the side reactions and thus improves the selectivity of propylene. This study investigated the Pt/K-Al₂O₃ and Pt-Mn/K-Al₂O₃ by varying the Pt/Mn ratio and the catalysts were tested for propane dehydrogenation lower temperature of 530 °C under Propane/H₂ ratio of 1:1. The catalyst showed stable performance with propylene selectivity of 90% and propane conversion of 45% for more than 24 h with 1.6 wt % coke deposition. The promising behavior of the catalyst was further investigated using characterization techniques such as EXAFS, XPS and TPR which indicated the strong interaction between Pt-Mn helpful for improving the selectivity of propylene. The particle size and existing phases of Pt-Mn were investigated using FETEM and XRD, respectively. Furthermore, an investigation on effect of GHSV and reaction temperature done elucidated that the lower reaction and higher GHSV favors the reaction in terms of achieving higher selectivity and stability. The regeneration step was done after 24 h of reaction and the activity was replenished indicating the good revitalization of catalytic activity.