Pt–Sn alloy phases and coke mobility over Pt–Sn/Al2O3 and Pt–Sn/ZnAl2O4 catalysts for propane dehydrogenation

The Effect of Tin–Support Interaction on Catalytic Stability over Pt–Sn/xAl–SBA-15 Catalysts for Propane Dehydrogenation

“…However, in the reduced Pt-Sn/Al 2 O 3 sample, no Pt-Sn alloy formation was observed due to a strong interaction between SnO x and Al 2 O 3 , which hinders the reducibility of SnO x to metallic Sn. This observation opposes our previous finding that there are two types of Pt-Sn alloys formed over an Al 2 O 3 support after reduction [27]. This difference can be explained by the fact that the Sn content is an important factor contributing to reducibility.…”

Effect of Sn Addition in Gas Phase Hydrogenation of Acetic Acid on Alumina Supported PtSn Catalysts

“…All the calcined catalysts show one sharp peak (486.6-487.1 eV) while the spectrum of the reduced catalysts can be resolved into 2 peaks (485.2-485.8 eV and 486.2-487.0 eV, respectively). The component at lower BE corresponds to zero-valent Sn or alloyed Sn, and that located at higher region can be ascribed to oxidic Sn [29][30][31]32].…”

Dehydroaromatization of methane over Sn–Pt modified Mo/H-ZSM-5 zeolite catalysts: Effect of preparation method

“…485.5 eV is associated with tin in the metallic state. It is worth noting that it is difficult to differentiate between the two tin oxide species (Sn 2+ and Sn 4+ ) by XPS [40,59]. Upon reduction the intensity of the band at lower binding energy associated with metallic tin increased.…”

“…Hence the introduction of tin species is to minimize the formation of carbon deposits on the Pt metal site. The tin oxide electronic effects will assist in minimizing the chemisorption of CH x species on platinum atoms and promote the migration of carbon deposits precursors from the metal surface to the support [40]. Zhou et al [71] reported that tin oxide also weakens the acidity of H-ZSM-5 whereby Brønsted acid sites are converted into Lewis acid sites and lead a reduced coke formation rate during the reaction.…”

“…The higher reduction temperature of MoO 2 to Mo (i.e. 767°C) could be attributed to the formation of Sn-Pt or Pt-Mo alloys that might inhibit platinum atoms from facilitating hydrogen spillover reaction which assists in enhancing the reducibility of molybdenum oxides[40]. The reducibility of molybdenum oxide in tin modified catalysts, calculated based on the first reduction step are presented inTable 1.…”