Sn-containing hexagonal mesoporous silica (HMS) for catalytic dehydrogenation of propane: An efficient strategy to enhance stability

Sn-containing hexagonal mesoporous silica (Sn-HMS) has been synthesized and evaluated for catalytic dehydrogenation of propane. XRD, HRTEM and XPS characterizations jointly evidence that, the Sn species are probably embedded into the lattice of HMS bulk at a relatively low Sn loading amount. Compared with Sn/SiO2 samples prepared by conventional impregnation method, Sn-HMS catalyst exhibits inspiringly higher propane conversion (similar to 40%) and better dehydrogenation stability up to 170 h, even after three oxidative regenerations. The improved stability of Sn-HMS catalyst is probably resulted from the inhibition of Sn reduction to low-melting-point metallic Sn species due to a strong Sn-O-Si bond, as well as the stabilization of the Sn species induced by the mesoporous structure of HMS substrate. Further, the reaction route of propane dehydrogenation over Sn-HMS catalyst has been proposed. (C) 2017 Elsevier Inc. All rights reserved.