Propane dehydrogenation over cobalt-based catalysts: Influence of Sn oxidation states upon catalytic stability through the MCM-41 framework

• Sn(II) doping enhanced Co/MCM-41 catalytic stability and activity for propane dehydrogenation. • Sn(II) doping led to increased pore volume and wider pore size, enhancing catalytic performance. • Co/Sn(II)@MCM-41 demonstrated 18.5 % propane conversion and 92 % propylene selectivity at 580 °C. • Sn(II) vs. Sn(IV) comparison revealed latter species lowers Co 2+ /Co 3+ ratio, reducing catalyst efficiency and selectivity. • Obtained excellent regenerability of Co/Sn(II)@MCM-41 maintaining consistent performance over 900 min of reaction. The development of cost-effective and environmentally benign catalysts for propane dehydrogenation (PDH) is critical for sustainable propylene production. In this study, cobalt-based catalysts supported on mesoporous MCM-41 were systematically modified via incorporation and impregnation of tin species with distinct oxidation states (Sn(II) and Sn(IV)) to investigate their influence upon catalytic activity and stability. Comprehensive physicochemical characterization, including XRD, BET-BJH, Raman, XPS, H 2 -TPR, NH 3 -TPD, and DRS, demonstrated that Sn(II) doping significantly enhanced the i) metal dispersion, ii) Co 2+ stabilization, and iii) mesoporous framework integrity. Amongst the synthesized catalysts, Co/Sn(II)@MCM-41 exhibited the highest Co 2+ /Co 3+ ratio (of 2.846), optimal acid site distribution, and superior textural properties, correlating with the best catalytic performance (of 18.5 % and 92 % for conversion and propylene selectivity, respectively), and the lowest deactivation rate (k d = 0.068 h −1 ) at 580 °C. In contrast, Sn(IV) incorporation results in a lower Co 2+ /Co 3+ ratio and weaker metal–support interactions, leading to a reduced population of active sites and inferior catalytic performance compared to that of Sn(II). These results highlighted the critical role of the tin oxidation state in tuning surface chemistry and catalyst durability. This work offers valuable insights toward the rational design of robust, non-noble metal catalysts for industrially relevant PDH processes.