Stable Pt catalysts anchored by Mn-SBA-15 support for propane dehydrogenation

The development of stable Pt-based catalysts is important for propane dehydrogenation process. In this work, Mn-SBA-15 supports with different Mn doping amounts were prepared by in situ hydrothermal method using citric acid and urea. Compared with Pt/SBA-15 catalyst, the significantly improved dispersion and stability of Pt on Pt/Mn-SBA-15 catalysts were demonstrated by X-ray diffraction and transmission electron microscopy results. CO DRIFT spectra analysis showed the electron transfer from Mn to Pt occurred, which led to an increase in the electron density of Pt. And the propane dehydrogenation performances over Pt/Mn-SBA-15 were enhanced significantly. Among them, the Pt/10Mn-SBA-15 shows the highest initial propane conversion of 51.2% and lowest deactivation rate constant of 0.013 h-1. The reason may be that appropriate amount of Mn can modify Pt by both electronic effect and geometric effect. And the strong metal-support interaction formed by highly dispersed MnOx anchor sites in Mn-SBA-15 support maintains the stability of Pt during the propane dehydrogenation reaction.