Restructuring effects of Pt and Fe in Pt/Fe-DMSN catalysts and their enhancement of propane dehydrogenation

Propane dehydrogenation (PDH) over Pt-based catalysts has drawn particular attention as a propene on-purpose production technology. The addition of a promoter and the dispersion of Pt have significant effects on catalytic performance. Herein, Fe-doped dendritic mesoporous silica nanoparticle (Fe-DMSN) supported Pt catalysts were developed, which show high catalytic activity and selectivity for PDH. We found that the reduction process induces redispersion rather than agglomeration of Pt, which is favorable for PDH reaction. UV-Vis diffuse reflectance spectroscopy (DRS) and Raman spectra revealed that the restructuring of Fe from aggregated FeOx species to isolated Fe3+ species occurred during the loading of Pt onto the Fe-DMSN supports as a resulting of the interaction between Pt and Fe. The stable isolated Fe3+ species promotes Pt redispersion during the reduction process, which results in a strong metal (Pt)–support (Fe-DMSN) interaction. A high catalytic activity for PDH, even during a 60 h long-term test, was obtained on Pt/0.4Fe-DMSN because of the strong interaction between the isolated Fe species and Pt species.