Coking-Resistant Sub-Nano Dehydrogenation Catalysts: Pt$_n$Sn$_x$/SiO$_2$ (n = 4, 7)
Skip to main content
eScholarship
Open Access Publications from the University of California

Coking-Resistant Sub-Nano Dehydrogenation Catalysts: Pt$_n$Sn$_x$/SiO$_2$ (n = 4, 7)

  • Author(s): Gorey, Timothy J
  • Zandkarimi, Borna
  • Li, Guangjing
  • Baxter, Eric T
  • Alexandrova, Anastassia N
  • Anderson, Scott L
  • et al.
Abstract

We present a combined experimental/theoretical study of Pt$_n$/SiO$_2$ and Pt$_n$Sn$_x$/SiO$_2$ (n = 4, 7) model catalysts for the endothermic dehydrogenation of hydrocarbons, using the ethylene intermediate as a model reactant. Supported pure Ptn clusters are found to be highly active toward dehydrogenation of C2D4, quickly deactivating due to a combination of carbon deposition and sintering, resulting in loss of accessible Pt sites. Addition of Sn to Ptn clusters results in the complete suppression of C2D4 dehydrogenation and carbon deposition, and also stabilizes the clusters against thermal sintering. Theory shows that both systems have thermal access to a multitude of cluster structures and adsorbate configurations that form a statistical ensemble. While Pt4/SiO2 clusters bind ethylene in both di-sigma and pi-bonded configurations, Pt$_4$Sn$_3$/SiO$_2$ binds C2H4 only in the pi-mode, with di-sigma bonding suppressed by a combination of electronic and geometric features of the PtSn clusters. Dehydrogenation reaction profiles on the accessible cluster isomers were calculated using the climbing image nudged elastic band (CI-NEB) method.

Many UC-authored scholarly publications are freely available on this site because of the UC's open access policies. Let us know how this access is important for you.

Main Content
Current View