The reaction of neopentane and hydrogen on oriented and non-oriented catalysts of Pt on Al2O3

Selectivity among Dehydrogenation Steps for Alkyl Groups on Metal Surfaces: Comparison between Nickel and Platinum

“…The catalytic H−D exchange on neopentane is sometimes accompanied by slower hydrogenolysis and isomerization processes. Three basic mechanisms have been proposed to explain those reactions: (1) a direct isomerization via an α,α,γ-tricoordinated bridged species; (2) the intermediate isomerization of that tricoordinated metallacycle to a monocoordinated cyclopentyl species; and (3) a methyl transfer via a cyclopentane-like intermediate, the same as in the bond-shift mechanism in carbonium ions. , It is interesting to point out, however, that isomerization reactions (from neopentane to 2-methylbutane in this case) are seen almost exclusively on platinum-based catalysts; ,,− no isomerization is observed in the case of nickel, only the production of isobutane (as well as smaller amounts of methane, ethane, and propane) . It could therefore be argued that an initial γ-hydride elimination step to a metallacyclic intermediate is required for skeletal rearrangement reactions and that this is only feasible on platinum, not nickel, substrates.…”

Electron Microscopy of Thin-Film Model Catalysts: Activation of Alumina-Supported Rhodium Nanoparticles

“…The regular habit of the asgrown metal nanocrystals provides a definite "initial state," a starting point to understand the microstructural changes during the following activation or regeneration or during a catalytic reaction. Moreover, metal particles grown epitaxially on large-area NaCl films provide enough surface area for kinetic measurements in a microreactor (21)(22)(23)(24).…”

Computerunterstütztes Mikroreaktorsystem zur Untersuchung heterogen katalysierter Gasreaktionen

“…der Hydrogenolyse zu Isobutan, n-Butan, Propan, Ethan und Methan an Platintragerkatalysatoren verwendet (vgl. dazu [24]). Als Test der Reproduzierbarkeit wurden zwei nicht aufeinanderfolgende Experimente an verschiedenen Tagen durchgefiihrt (Abb.…”