Deactivation origins and stability-enhancing strategies of Sn/SiO2 catalysts for ethane dehydrogenation

A low-cost and environment-friendly Sn/SiO2 catalyst, highly active and selective for ethane dehydrogenation, is an effective alternative for high-cost Pt and toxic CrOx-based catalysts. While the catalyst deactivates fast due to the loss and aggregation of Sn species. In order to solve the problem, complexation impregnation method and in-situ synthesis approach have been tried to enhance the stability of Sn-based catalyst. As for the former one, a relatively stable performance of 5Sn/SiO2 catalyst can be achieved due to depressed Sn loss and coke deposition, while there is still room for improvement. When the latter strategy is applied, 5Sn-MCM-41 catalyst demonstrates the optimal dehydrogenation performance, with 44.0% of ethane conversion and 98.8% of ethylene selectivity, and no obvious decreasing trend is observed in the progress of 18 h reaction due to the well dispersion and anchoring of Sn species on the framework of MCM-41.